diff --git a/package.json b/package.json
index bbeb5942..da109d2e 100644
--- a/package.json
+++ b/package.json
@@ -23,6 +23,7 @@
     "https-proxy-agent": "2.2.1",
     "jsonschema": "1.2.2",
     "lodash": "^4.17.4",
+    "lodash.isequal": "^4.5.0",
     "ripple-address-codec": "^3.0.4",
     "ripple-binary-codec": "^0.2.4",
     "ripple-keypairs": "^0.10.1",
@@ -57,7 +58,7 @@
     "doctoc": "doctoc docs/index.md --title '# RippleAPI Reference' --github --maxlevel 2",
     "docgen": "node --harmony scripts/build_docs.js",
     "clean": "rm -rf dist/npm",
-    "compile": "mkdir -p dist/npm/common/js && cp -r src/common/js/ dist/npm/common/js/ && mkdir -p dist/npm/common && cp -r src/common/schemas dist/npm/common/ && tsc --build",
+    "compile": "mkdir -p dist/npm/common && cp -r src/common/schemas dist/npm/common/ && tsc --build",
     "watch": "tsc -w",
     "prepublish": "npm run clean && npm run compile && npm run build",
     "test": "TS_NODE_PROJECT=src/tsconfig.json nyc mocha --exit",
diff --git a/src/common/connection.ts b/src/common/connection.ts
index b8fe47a5..d9fb5fc7 100644
--- a/src/common/connection.ts
+++ b/src/common/connection.ts
@@ -1,7 +1,7 @@
 import * as _ from 'lodash'
 import {EventEmitter} from 'events'
 import {parse as parseUrl} from 'url'
-import * as WebSocket from 'ws'
+import WebSocket from 'ws'
 import RangeSet from './rangeset'
 import {RippledError, DisconnectedError, NotConnectedError,
   TimeoutError, ResponseFormatError, ConnectionError,
diff --git a/src/common/hashes/README.md b/src/common/hashes/README.md
new file mode 100644
index 00000000..8b4a27e6
--- /dev/null
+++ b/src/common/hashes/README.md
@@ -0,0 +1,49 @@
+# XRP Ledger Hashes
+
+Methods to hash XRP Ledger objects
+
+## Methods
+
+### computeBinaryTransactionHash = (txBlobHex: string): string
+
+Compute the hash of a binary transaction blob.
+
+### computeTransactionHash = (txJSON: any): string
+
+Compute the hash of a transaction in txJSON format.
+
+### computeBinaryTransactionSigningHash = (txBlobHex: string): string
+
+### computeTransactionSigningHash = (txJSON: any): string
+
+### computeAccountHash = (address: string): string
+
+Compute the hash of an account, given the account's classic address (starting with `r`).
+
+### computeSignerListHash = (address: string): string
+
+Compute the hash of an account's SignerList.
+
+### computeOrderHash = (address: string, sequence: number): string
+
+Compute the hash of an order, given the owner's classic address (starting with `r`) and the account sequence number of the `OfferCreate` order transaction.
+
+### computeTrustlineHash = (address1: string, address2: string, currency: string): string
+
+Compute the hash of a trustline, given the two parties' classic addresses (starting with `r`) and the currency code.
+
+### computeTransactionTreeHash = (transactions: any[]): string
+
+### computeStateTreeHash = (entries: any[]): string
+
+### computeLedgerHash = (ledgerHeader): string
+
+Compute the hash of a ledger.
+
+### computeEscrowHash = (address, sequence): string
+
+Compute the hash of an escrow, given the owner's classic address (starting with `r`) and the account sequence number of the `EscrowCreate` escrow transaction.
+
+### computePaymentChannelHash = (address, dstAddress, sequence): string
+
+Compute the hash of a payment channel, given the owner's classic address (starting with `r`), the classic address of the destination, and the account sequence number of the `PaymentChannelCreate` payment channel transaction.
diff --git a/src/common/js/lodash.isequal.js b/src/common/js/lodash.isequal.js
deleted file mode 100644
index 9fc0281b..00000000
--- a/src/common/js/lodash.isequal.js
+++ /dev/null
@@ -1,1649 +0,0 @@
-/**
- * lodash (Custom Build) <https://lodash.com/>
- * Build: `lodash modularize exports="npm" -o ./`
- * Copyright jQuery Foundation and other contributors <https://jquery.org/>
- * Released under MIT license <https://lodash.com/license>
- * Based on Underscore.js 1.8.3 <http://underscorejs.org/LICENSE>
- * Copyright Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
- */
-
-/** Used as the size to enable large array optimizations. */
-var LARGE_ARRAY_SIZE = 200;
-
-/** Used to stand-in for `undefined` hash values. */
-var HASH_UNDEFINED = '__lodash_hash_undefined__';
-
-/** Used to compose bitmasks for comparison styles. */
-var UNORDERED_COMPARE_FLAG = 1,
-    PARTIAL_COMPARE_FLAG = 2;
-
-/** Used as references for various `Number` constants. */
-var MAX_SAFE_INTEGER = 9007199254740991;
-
-/** `Object#toString` result references. */
-var argsTag = '[object Arguments]',
-    arrayTag = '[object Array]',
-    boolTag = '[object Boolean]',
-    dateTag = '[object Date]',
-    errorTag = '[object Error]',
-    funcTag = '[object Function]',
-    genTag = '[object GeneratorFunction]',
-    mapTag = '[object Map]',
-    numberTag = '[object Number]',
-    objectTag = '[object Object]',
-    promiseTag = '[object Promise]',
-    regexpTag = '[object RegExp]',
-    setTag = '[object Set]',
-    stringTag = '[object String]',
-    symbolTag = '[object Symbol]',
-    weakMapTag = '[object WeakMap]';
-
-var arrayBufferTag = '[object ArrayBuffer]',
-    dataViewTag = '[object DataView]',
-    float32Tag = '[object Float32Array]',
-    float64Tag = '[object Float64Array]',
-    int8Tag = '[object Int8Array]',
-    int16Tag = '[object Int16Array]',
-    int32Tag = '[object Int32Array]',
-    uint8Tag = '[object Uint8Array]',
-    uint8ClampedTag = '[object Uint8ClampedArray]',
-    uint16Tag = '[object Uint16Array]',
-    uint32Tag = '[object Uint32Array]';
-
-/**
- * Used to match `RegExp`
- * [syntax characters](http://ecma-international.org/ecma-262/7.0/#sec-patterns).
- */
-var reRegExpChar = /[\\^$.*+?()[\]{}|]/g;
-
-/** Used to detect host constructors (Safari). */
-var reIsHostCtor = /^\[object .+?Constructor\]$/;
-
-/** Used to detect unsigned integer values. */
-var reIsUint = /^(?:0|[1-9]\d*)$/;
-
-/** Used to identify `toStringTag` values of typed arrays. */
-var typedArrayTags = {};
-typedArrayTags[float32Tag] = typedArrayTags[float64Tag] =
-typedArrayTags[int8Tag] = typedArrayTags[int16Tag] =
-typedArrayTags[int32Tag] = typedArrayTags[uint8Tag] =
-typedArrayTags[uint8ClampedTag] = typedArrayTags[uint16Tag] =
-typedArrayTags[uint32Tag] = true;
-typedArrayTags[argsTag] = typedArrayTags[arrayTag] =
-typedArrayTags[arrayBufferTag] = typedArrayTags[boolTag] =
-typedArrayTags[dataViewTag] = typedArrayTags[dateTag] =
-typedArrayTags[errorTag] = typedArrayTags[funcTag] =
-typedArrayTags[mapTag] = typedArrayTags[numberTag] =
-typedArrayTags[objectTag] = typedArrayTags[regexpTag] =
-typedArrayTags[setTag] = typedArrayTags[stringTag] =
-typedArrayTags[weakMapTag] = false;
-
-/** Detect free variable `global` from Node.js. */
-var freeGlobal = typeof global == 'object' && global && global.Object === Object && global;
-
-/** Detect free variable `self`. */
-var freeSelf = typeof self == 'object' && self && self.Object === Object && self;
-
-/** Used as a reference to the global object. */
-var root = freeGlobal || freeSelf || Function('return this')();
-
-/** Detect free variable `exports`. */
-var freeExports = typeof exports == 'object' && exports && !exports.nodeType && exports;
-
-/** Detect free variable `module`. */
-var freeModule = freeExports && typeof module == 'object' && module && !module.nodeType && module;
-
-/** Detect the popular CommonJS extension `module.exports`. */
-var moduleExports = freeModule && freeModule.exports === freeExports;
-
-/** Detect free variable `process` from Node.js. */
-var freeProcess = moduleExports && freeGlobal.process;
-
-/** Used to access faster Node.js helpers. */
-var nodeUtil = (function() {
-  try {
-    return freeProcess && freeProcess.binding('util');
-  } catch (e) {}
-}());
-
-/* Node.js helper references. */
-var nodeIsTypedArray = nodeUtil && nodeUtil.isTypedArray;
-
-/**
- * A specialized version of `_.some` for arrays without support for iteratee
- * shorthands.
- *
- * @private
- * @param {Array} [array] The array to iterate over.
- * @param {Function} predicate The function invoked per iteration.
- * @returns {boolean} Returns `true` if any element passes the predicate check,
- *  else `false`.
- */
-function arraySome(array, predicate) {
-  var index = -1,
-      length = array ? array.length : 0;
-
-  while (++index < length) {
-    if (predicate(array[index], index, array)) {
-      return true;
-    }
-  }
-  return false;
-}
-
-/**
- * The base implementation of `_.times` without support for iteratee shorthands
- * or max array length checks.
- *
- * @private
- * @param {number} n The number of times to invoke `iteratee`.
- * @param {Function} iteratee The function invoked per iteration.
- * @returns {Array} Returns the array of results.
- */
-function baseTimes(n, iteratee) {
-  var index = -1,
-      result = Array(n);
-
-  while (++index < n) {
-    result[index] = iteratee(index);
-  }
-  return result;
-}
-
-/**
- * The base implementation of `_.unary` without support for storing metadata.
- *
- * @private
- * @param {Function} func The function to cap arguments for.
- * @returns {Function} Returns the new capped function.
- */
-function baseUnary(func) {
-  return function(value) {
-    return func(value);
-  };
-}
-
-/**
- * Gets the value at `key` of `object`.
- *
- * @private
- * @param {Object} [object] The object to query.
- * @param {string} key The key of the property to get.
- * @returns {*} Returns the property value.
- */
-function getValue(object, key) {
-  return object == null ? undefined : object[key];
-}
-
-/**
- * Checks if `value` is a host object in IE < 9.
- *
- * @private
- * @param {*} value The value to check.
- * @returns {boolean} Returns `true` if `value` is a host object, else `false`.
- */
-function isHostObject(value) {
-  // Many host objects are `Object` objects that can coerce to strings
-  // despite having improperly defined `toString` methods.
-  var result = false;
-  if (value != null && typeof value.toString != 'function') {
-    try {
-      result = !!(value + '');
-    } catch (e) {}
-  }
-  return result;
-}
-
-/**
- * Converts `map` to its key-value pairs.
- *
- * @private
- * @param {Object} map The map to convert.
- * @returns {Array} Returns the key-value pairs.
- */
-function mapToArray(map) {
-  var index = -1,
-      result = Array(map.size);
-
-  map.forEach(function(value, key) {
-    result[++index] = [key, value];
-  });
-  return result;
-}
-
-/**
- * Creates a unary function that invokes `func` with its argument transformed.
- *
- * @private
- * @param {Function} func The function to wrap.
- * @param {Function} transform The argument transform.
- * @returns {Function} Returns the new function.
- */
-function overArg(func, transform) {
-  return function(arg) {
-    return func(transform(arg));
-  };
-}
-
-/**
- * Converts `set` to an array of its values.
- *
- * @private
- * @param {Object} set The set to convert.
- * @returns {Array} Returns the values.
- */
-function setToArray(set) {
-  var index = -1,
-      result = Array(set.size);
-
-  set.forEach(function(value) {
-    result[++index] = value;
-  });
-  return result;
-}
-
-/** Used for built-in method references. */
-var arrayProto = Array.prototype,
-    funcProto = Function.prototype,
-    objectProto = Object.prototype;
-
-/** Used to detect overreaching core-js shims. */
-var coreJsData = root['__core-js_shared__'];
-
-/** Used to detect methods masquerading as native. */
-var maskSrcKey = (function() {
-  var uid = /[^.]+$/.exec(coreJsData && coreJsData.keys && coreJsData.keys.IE_PROTO || '');
-  return uid ? ('Symbol(src)_1.' + uid) : '';
-}());
-
-/** Used to resolve the decompiled source of functions. */
-var funcToString = funcProto.toString;
-
-/** Used to check objects for own properties. */
-var hasOwnProperty = objectProto.hasOwnProperty;
-
-/**
- * Used to resolve the
- * [`toStringTag`](http://ecma-international.org/ecma-262/7.0/#sec-object.prototype.tostring)
- * of values.
- */
-var objectToString = objectProto.toString;
-
-/** Used to detect if a method is native. */
-var reIsNative = RegExp('^' +
-  funcToString.call(hasOwnProperty).replace(reRegExpChar, '\\$&')
-  .replace(/hasOwnProperty|(function).*?(?=\\\()| for .+?(?=\\\])/g, '$1.*?') + '$'
-);
-
-/** Built-in value references. */
-var Symbol = root.Symbol,
-    Uint8Array = root.Uint8Array,
-    propertyIsEnumerable = objectProto.propertyIsEnumerable,
-    splice = arrayProto.splice;
-
-/* Built-in method references for those with the same name as other `lodash` methods. */
-var nativeKeys = overArg(Object.keys, Object);
-
-/* Built-in method references that are verified to be native. */
-var DataView = getNative(root, 'DataView'),
-    Map = getNative(root, 'Map'),
-    Promise = getNative(root, 'Promise'),
-    Set = getNative(root, 'Set'),
-    WeakMap = getNative(root, 'WeakMap'),
-    nativeCreate = getNative(Object, 'create');
-
-/** Used to detect maps, sets, and weakmaps. */
-var dataViewCtorString = toSource(DataView),
-    mapCtorString = toSource(Map),
-    promiseCtorString = toSource(Promise),
-    setCtorString = toSource(Set),
-    weakMapCtorString = toSource(WeakMap);
-
-/** Used to convert symbols to primitives and strings. */
-var symbolProto = Symbol ? Symbol.prototype : undefined,
-    symbolValueOf = symbolProto ? symbolProto.valueOf : undefined;
-
-/**
- * Creates a hash object.
- *
- * @private
- * @constructor
- * @param {Array} [entries] The key-value pairs to cache.
- */
-function Hash(entries) {
-  var index = -1,
-      length = entries ? entries.length : 0;
-
-  this.clear();
-  while (++index < length) {
-    var entry = entries[index];
-    this.set(entry[0], entry[1]);
-  }
-}
-
-/**
- * Removes all key-value entries from the hash.
- *
- * @private
- * @name clear
- * @memberOf Hash
- */
-function hashClear() {
-  this.__data__ = nativeCreate ? nativeCreate(null) : {};
-}
-
-/**
- * Removes `key` and its value from the hash.
- *
- * @private
- * @name delete
- * @memberOf Hash
- * @param {Object} hash The hash to modify.
- * @param {string} key The key of the value to remove.
- * @returns {boolean} Returns `true` if the entry was removed, else `false`.
- */
-function hashDelete(key) {
-  return this.has(key) && delete this.__data__[key];
-}
-
-/**
- * Gets the hash value for `key`.
- *
- * @private
- * @name get
- * @memberOf Hash
- * @param {string} key The key of the value to get.
- * @returns {*} Returns the entry value.
- */
-function hashGet(key) {
-  var data = this.__data__;
-  if (nativeCreate) {
-    var result = data[key];
-    return result === HASH_UNDEFINED ? undefined : result;
-  }
-  return hasOwnProperty.call(data, key) ? data[key] : undefined;
-}
-
-/**
- * Checks if a hash value for `key` exists.
- *
- * @private
- * @name has
- * @memberOf Hash
- * @param {string} key The key of the entry to check.
- * @returns {boolean} Returns `true` if an entry for `key` exists, else `false`.
- */
-function hashHas(key) {
-  var data = this.__data__;
-  return nativeCreate ? data[key] !== undefined : hasOwnProperty.call(data, key);
-}
-
-/**
- * Sets the hash `key` to `value`.
- *
- * @private
- * @name set
- * @memberOf Hash
- * @param {string} key The key of the value to set.
- * @param {*} value The value to set.
- * @returns {Object} Returns the hash instance.
- */
-function hashSet(key, value) {
-  var data = this.__data__;
-  data[key] = (nativeCreate && value === undefined) ? HASH_UNDEFINED : value;
-  return this;
-}
-
-// Add methods to `Hash`.
-Hash.prototype.clear = hashClear;
-Hash.prototype['delete'] = hashDelete;
-Hash.prototype.get = hashGet;
-Hash.prototype.has = hashHas;
-Hash.prototype.set = hashSet;
-
-/**
- * Creates an list cache object.
- *
- * @private
- * @constructor
- * @param {Array} [entries] The key-value pairs to cache.
- */
-function ListCache(entries) {
-  var index = -1,
-      length = entries ? entries.length : 0;
-
-  this.clear();
-  while (++index < length) {
-    var entry = entries[index];
-    this.set(entry[0], entry[1]);
-  }
-}
-
-/**
- * Removes all key-value entries from the list cache.
- *
- * @private
- * @name clear
- * @memberOf ListCache
- */
-function listCacheClear() {
-  this.__data__ = [];
-}
-
-/**
- * Removes `key` and its value from the list cache.
- *
- * @private
- * @name delete
- * @memberOf ListCache
- * @param {string} key The key of the value to remove.
- * @returns {boolean} Returns `true` if the entry was removed, else `false`.
- */
-function listCacheDelete(key) {
-  var data = this.__data__,
-      index = assocIndexOf(data, key);
-
-  if (index < 0) {
-    return false;
-  }
-  var lastIndex = data.length - 1;
-  if (index == lastIndex) {
-    data.pop();
-  } else {
-    splice.call(data, index, 1);
-  }
-  return true;
-}
-
-/**
- * Gets the list cache value for `key`.
- *
- * @private
- * @name get
- * @memberOf ListCache
- * @param {string} key The key of the value to get.
- * @returns {*} Returns the entry value.
- */
-function listCacheGet(key) {
-  var data = this.__data__,
-      index = assocIndexOf(data, key);
-
-  return index < 0 ? undefined : data[index][1];
-}
-
-/**
- * Checks if a list cache value for `key` exists.
- *
- * @private
- * @name has
- * @memberOf ListCache
- * @param {string} key The key of the entry to check.
- * @returns {boolean} Returns `true` if an entry for `key` exists, else `false`.
- */
-function listCacheHas(key) {
-  return assocIndexOf(this.__data__, key) > -1;
-}
-
-/**
- * Sets the list cache `key` to `value`.
- *
- * @private
- * @name set
- * @memberOf ListCache
- * @param {string} key The key of the value to set.
- * @param {*} value The value to set.
- * @returns {Object} Returns the list cache instance.
- */
-function listCacheSet(key, value) {
-  var data = this.__data__,
-      index = assocIndexOf(data, key);
-
-  if (index < 0) {
-    data.push([key, value]);
-  } else {
-    data[index][1] = value;
-  }
-  return this;
-}
-
-// Add methods to `ListCache`.
-ListCache.prototype.clear = listCacheClear;
-ListCache.prototype['delete'] = listCacheDelete;
-ListCache.prototype.get = listCacheGet;
-ListCache.prototype.has = listCacheHas;
-ListCache.prototype.set = listCacheSet;
-
-/**
- * Creates a map cache object to store key-value pairs.
- *
- * @private
- * @constructor
- * @param {Array} [entries] The key-value pairs to cache.
- */
-function MapCache(entries) {
-  var index = -1,
-      length = entries ? entries.length : 0;
-
-  this.clear();
-  while (++index < length) {
-    var entry = entries[index];
-    this.set(entry[0], entry[1]);
-  }
-}
-
-/**
- * Removes all key-value entries from the map.
- *
- * @private
- * @name clear
- * @memberOf MapCache
- */
-function mapCacheClear() {
-  this.__data__ = {
-    'hash': new Hash,
-    'map': new (Map || ListCache),
-    'string': new Hash
-  };
-}
-
-/**
- * Removes `key` and its value from the map.
- *
- * @private
- * @name delete
- * @memberOf MapCache
- * @param {string} key The key of the value to remove.
- * @returns {boolean} Returns `true` if the entry was removed, else `false`.
- */
-function mapCacheDelete(key) {
-  return getMapData(this, key)['delete'](key);
-}
-
-/**
- * Gets the map value for `key`.
- *
- * @private
- * @name get
- * @memberOf MapCache
- * @param {string} key The key of the value to get.
- * @returns {*} Returns the entry value.
- */
-function mapCacheGet(key) {
-  return getMapData(this, key).get(key);
-}
-
-/**
- * Checks if a map value for `key` exists.
- *
- * @private
- * @name has
- * @memberOf MapCache
- * @param {string} key The key of the entry to check.
- * @returns {boolean} Returns `true` if an entry for `key` exists, else `false`.
- */
-function mapCacheHas(key) {
-  return getMapData(this, key).has(key);
-}
-
-/**
- * Sets the map `key` to `value`.
- *
- * @private
- * @name set
- * @memberOf MapCache
- * @param {string} key The key of the value to set.
- * @param {*} value The value to set.
- * @returns {Object} Returns the map cache instance.
- */
-function mapCacheSet(key, value) {
-  getMapData(this, key).set(key, value);
-  return this;
-}
-
-// Add methods to `MapCache`.
-MapCache.prototype.clear = mapCacheClear;
-MapCache.prototype['delete'] = mapCacheDelete;
-MapCache.prototype.get = mapCacheGet;
-MapCache.prototype.has = mapCacheHas;
-MapCache.prototype.set = mapCacheSet;
-
-/**
- *
- * Creates an array cache object to store unique values.
- *
- * @private
- * @constructor
- * @param {Array} [values] The values to cache.
- */
-function SetCache(values) {
-  var index = -1,
-      length = values ? values.length : 0;
-
-  this.__data__ = new MapCache;
-  while (++index < length) {
-    this.add(values[index]);
-  }
-}
-
-/**
- * Adds `value` to the array cache.
- *
- * @private
- * @name add
- * @memberOf SetCache
- * @alias push
- * @param {*} value The value to cache.
- * @returns {Object} Returns the cache instance.
- */
-function setCacheAdd(value) {
-  this.__data__.set(value, HASH_UNDEFINED);
-  return this;
-}
-
-/**
- * Checks if `value` is in the array cache.
- *
- * @private
- * @name has
- * @memberOf SetCache
- * @param {*} value The value to search for.
- * @returns {number} Returns `true` if `value` is found, else `false`.
- */
-function setCacheHas(value) {
-  return this.__data__.has(value);
-}
-
-// Add methods to `SetCache`.
-SetCache.prototype.add = SetCache.prototype.push = setCacheAdd;
-SetCache.prototype.has = setCacheHas;
-
-/**
- * Creates a stack cache object to store key-value pairs.
- *
- * @private
- * @constructor
- * @param {Array} [entries] The key-value pairs to cache.
- */
-function Stack(entries) {
-  this.__data__ = new ListCache(entries);
-}
-
-/**
- * Removes all key-value entries from the stack.
- *
- * @private
- * @name clear
- * @memberOf Stack
- */
-function stackClear() {
-  this.__data__ = new ListCache;
-}
-
-/**
- * Removes `key` and its value from the stack.
- *
- * @private
- * @name delete
- * @memberOf Stack
- * @param {string} key The key of the value to remove.
- * @returns {boolean} Returns `true` if the entry was removed, else `false`.
- */
-function stackDelete(key) {
-  return this.__data__['delete'](key);
-}
-
-/**
- * Gets the stack value for `key`.
- *
- * @private
- * @name get
- * @memberOf Stack
- * @param {string} key The key of the value to get.
- * @returns {*} Returns the entry value.
- */
-function stackGet(key) {
-  return this.__data__.get(key);
-}
-
-/**
- * Checks if a stack value for `key` exists.
- *
- * @private
- * @name has
- * @memberOf Stack
- * @param {string} key The key of the entry to check.
- * @returns {boolean} Returns `true` if an entry for `key` exists, else `false`.
- */
-function stackHas(key) {
-  return this.__data__.has(key);
-}
-
-/**
- * Sets the stack `key` to `value`.
- *
- * @private
- * @name set
- * @memberOf Stack
- * @param {string} key The key of the value to set.
- * @param {*} value The value to set.
- * @returns {Object} Returns the stack cache instance.
- */
-function stackSet(key, value) {
-  var cache = this.__data__;
-  if (cache instanceof ListCache) {
-    var pairs = cache.__data__;
-    if (!Map || (pairs.length < LARGE_ARRAY_SIZE - 1)) {
-      pairs.push([key, value]);
-      return this;
-    }
-    cache = this.__data__ = new MapCache(pairs);
-  }
-  cache.set(key, value);
-  return this;
-}
-
-// Add methods to `Stack`.
-Stack.prototype.clear = stackClear;
-Stack.prototype['delete'] = stackDelete;
-Stack.prototype.get = stackGet;
-Stack.prototype.has = stackHas;
-Stack.prototype.set = stackSet;
-
-/**
- * Creates an array of the enumerable property names of the array-like `value`.
- *
- * @private
- * @param {*} value The value to query.
- * @param {boolean} inherited Specify returning inherited property names.
- * @returns {Array} Returns the array of property names.
- */
-function arrayLikeKeys(value, inherited) {
-  // Safari 8.1 makes `arguments.callee` enumerable in strict mode.
-  // Safari 9 makes `arguments.length` enumerable in strict mode.
-  var result = (isArray(value) || isArguments(value))
-    ? baseTimes(value.length, String)
-    : [];
-
-  var length = result.length,
-      skipIndexes = !!length;
-
-  for (var key in value) {
-    if ((inherited || hasOwnProperty.call(value, key)) &&
-        !(skipIndexes && (key == 'length' || isIndex(key, length)))) {
-      result.push(key);
-    }
-  }
-  return result;
-}
-
-/**
- * Gets the index at which the `key` is found in `array` of key-value pairs.
- *
- * @private
- * @param {Array} array The array to inspect.
- * @param {*} key The key to search for.
- * @returns {number} Returns the index of the matched value, else `-1`.
- */
-function assocIndexOf(array, key) {
-  var length = array.length;
-  while (length--) {
-    if (eq(array[length][0], key)) {
-      return length;
-    }
-  }
-  return -1;
-}
-
-/**
- * The base implementation of `getTag`.
- *
- * @private
- * @param {*} value The value to query.
- * @returns {string} Returns the `toStringTag`.
- */
-function baseGetTag(value) {
-  return objectToString.call(value);
-}
-
-/**
- * The base implementation of `_.isEqual` which supports partial comparisons
- * and tracks traversed objects.
- *
- * @private
- * @param {*} value The value to compare.
- * @param {*} other The other value to compare.
- * @param {Function} [customizer] The function to customize comparisons.
- * @param {boolean} [bitmask] The bitmask of comparison flags.
- *  The bitmask may be composed of the following flags:
- *     1 - Unordered comparison
- *     2 - Partial comparison
- * @param {Object} [stack] Tracks traversed `value` and `other` objects.
- * @returns {boolean} Returns `true` if the values are equivalent, else `false`.
- */
-function baseIsEqual(value, other, customizer, bitmask, stack) {
-  if (value === other) {
-    return true;
-  }
-  if (value == null || other == null || (!isObject(value) && !isObjectLike(other))) {
-    return value !== value && other !== other;
-  }
-  return baseIsEqualDeep(value, other, baseIsEqual, customizer, bitmask, stack);
-}
-
-/**
- * A specialized version of `baseIsEqual` for arrays and objects which performs
- * deep comparisons and tracks traversed objects enabling objects with circular
- * references to be compared.
- *
- * @private
- * @param {Object} object The object to compare.
- * @param {Object} other The other object to compare.
- * @param {Function} equalFunc The function to determine equivalents of values.
- * @param {Function} [customizer] The function to customize comparisons.
- * @param {number} [bitmask] The bitmask of comparison flags. See `baseIsEqual`
- *  for more details.
- * @param {Object} [stack] Tracks traversed `object` and `other` objects.
- * @returns {boolean} Returns `true` if the objects are equivalent, else `false`.
- */
-function baseIsEqualDeep(object, other, equalFunc, customizer, bitmask, stack) {
-  var objIsArr = isArray(object),
-      othIsArr = isArray(other),
-      objTag = arrayTag,
-      othTag = arrayTag;
-
-  if (!objIsArr) {
-    objTag = getTag(object);
-    objTag = objTag == argsTag ? objectTag : objTag;
-  }
-  if (!othIsArr) {
-    othTag = getTag(other);
-    othTag = othTag == argsTag ? objectTag : othTag;
-  }
-  var objIsObj = objTag == objectTag && !isHostObject(object),
-      othIsObj = othTag == objectTag && !isHostObject(other),
-      isSameTag = objTag == othTag;
-
-  if (isSameTag && !objIsObj) {
-    stack || (stack = new Stack);
-    return (objIsArr || isTypedArray(object))
-      ? equalArrays(object, other, equalFunc, customizer, bitmask, stack)
-      : equalByTag(object, other, objTag, equalFunc, customizer, bitmask, stack);
-  }
-  if (!(bitmask & PARTIAL_COMPARE_FLAG)) {
-    var objIsWrapped = objIsObj && hasOwnProperty.call(object, '__wrapped__'),
-        othIsWrapped = othIsObj && hasOwnProperty.call(other, '__wrapped__');
-
-    if (objIsWrapped || othIsWrapped) {
-      var objUnwrapped = objIsWrapped ? object.value() : object,
-          othUnwrapped = othIsWrapped ? other.value() : other;
-
-      stack || (stack = new Stack);
-      return equalFunc(objUnwrapped, othUnwrapped, customizer, bitmask, stack);
-    }
-  }
-  if (!isSameTag) {
-    return false;
-  }
-  stack || (stack = new Stack);
-  return equalObjects(object, other, equalFunc, customizer, bitmask, stack);
-}
-
-/**
- * The base implementation of `_.isNative` without bad shim checks.
- *
- * @private
- * @param {*} value The value to check.
- * @returns {boolean} Returns `true` if `value` is a native function,
- *  else `false`.
- */
-function baseIsNative(value) {
-  if (!isObject(value) || isMasked(value)) {
-    return false;
-  }
-  var pattern = (isFunction(value) || isHostObject(value)) ? reIsNative : reIsHostCtor;
-  return pattern.test(toSource(value));
-}
-
-/**
- * The base implementation of `_.isTypedArray` without Node.js optimizations.
- *
- * @private
- * @param {*} value The value to check.
- * @returns {boolean} Returns `true` if `value` is a typed array, else `false`.
- */
-function baseIsTypedArray(value) {
-  return isObjectLike(value) &&
-    isLength(value.length) && !!typedArrayTags[objectToString.call(value)];
-}
-
-/**
- * The base implementation of `_.keys` which doesn't treat sparse arrays as dense.
- *
- * @private
- * @param {Object} object The object to query.
- * @returns {Array} Returns the array of property names.
- */
-function baseKeys(object) {
-  if (!isPrototype(object)) {
-    return nativeKeys(object);
-  }
-  var result = [];
-  for (var key in Object(object)) {
-    if (hasOwnProperty.call(object, key) && key != 'constructor') {
-      result.push(key);
-    }
-  }
-  return result;
-}
-
-/**
- * A specialized version of `baseIsEqualDeep` for arrays with support for
- * partial deep comparisons.
- *
- * @private
- * @param {Array} array The array to compare.
- * @param {Array} other The other array to compare.
- * @param {Function} equalFunc The function to determine equivalents of values.
- * @param {Function} customizer The function to customize comparisons.
- * @param {number} bitmask The bitmask of comparison flags. See `baseIsEqual`
- *  for more details.
- * @param {Object} stack Tracks traversed `array` and `other` objects.
- * @returns {boolean} Returns `true` if the arrays are equivalent, else `false`.
- */
-function equalArrays(array, other, equalFunc, customizer, bitmask, stack) {
-  var isPartial = bitmask & PARTIAL_COMPARE_FLAG,
-      arrLength = array.length,
-      othLength = other.length;
-
-  if (arrLength != othLength && !(isPartial && othLength > arrLength)) {
-    return false;
-  }
-  // Assume cyclic values are equal.
-  var stacked = stack.get(array);
-  if (stacked && stack.get(other)) {
-    return stacked == other;
-  }
-  var index = -1,
-      result = true,
-      seen = (bitmask & UNORDERED_COMPARE_FLAG) ? new SetCache : undefined;
-
-  stack.set(array, other);
-  stack.set(other, array);
-
-  // Ignore non-index properties.
-  while (++index < arrLength) {
-    var arrValue = array[index],
-        othValue = other[index];
-
-    if (customizer) {
-      var compared = isPartial
-        ? customizer(othValue, arrValue, index, other, array, stack)
-        : customizer(arrValue, othValue, index, array, other, stack);
-    }
-    if (compared !== undefined) {
-      if (compared) {
-        continue;
-      }
-      result = false;
-      break;
-    }
-    // Recursively compare arrays (susceptible to call stack limits).
-    if (seen) {
-      if (!arraySome(other, function(othValue, othIndex) {
-            if (!seen.has(othIndex) &&
-                (arrValue === othValue || equalFunc(arrValue, othValue, customizer, bitmask, stack))) {
-              return seen.add(othIndex);
-            }
-          })) {
-        result = false;
-        break;
-      }
-    } else if (!(
-          arrValue === othValue ||
-            equalFunc(arrValue, othValue, customizer, bitmask, stack)
-        )) {
-      result = false;
-      break;
-    }
-  }
-  stack['delete'](array);
-  stack['delete'](other);
-  return result;
-}
-
-/**
- * A specialized version of `baseIsEqualDeep` for comparing objects of
- * the same `toStringTag`.
- *
- * **Note:** This function only supports comparing values with tags of
- * `Boolean`, `Date`, `Error`, `Number`, `RegExp`, or `String`.
- *
- * @private
- * @param {Object} object The object to compare.
- * @param {Object} other The other object to compare.
- * @param {string} tag The `toStringTag` of the objects to compare.
- * @param {Function} equalFunc The function to determine equivalents of values.
- * @param {Function} customizer The function to customize comparisons.
- * @param {number} bitmask The bitmask of comparison flags. See `baseIsEqual`
- *  for more details.
- * @param {Object} stack Tracks traversed `object` and `other` objects.
- * @returns {boolean} Returns `true` if the objects are equivalent, else `false`.
- */
-function equalByTag(object, other, tag, equalFunc, customizer, bitmask, stack) {
-  switch (tag) {
-    case dataViewTag:
-      if ((object.byteLength != other.byteLength) ||
-          (object.byteOffset != other.byteOffset)) {
-        return false;
-      }
-      object = object.buffer;
-      other = other.buffer;
-
-    case arrayBufferTag:
-      if ((object.byteLength != other.byteLength) ||
-          !equalFunc(new Uint8Array(object), new Uint8Array(other))) {
-        return false;
-      }
-      return true;
-
-    case boolTag:
-    case dateTag:
-    case numberTag:
-      // Coerce booleans to `1` or `0` and dates to milliseconds.
-      // Invalid dates are coerced to `NaN`.
-      return eq(+object, +other);
-
-    case errorTag:
-      return object.name == other.name && object.message == other.message;
-
-    case regexpTag:
-    case stringTag:
-      // Coerce regexes to strings and treat strings, primitives and objects,
-      // as equal. See http://www.ecma-international.org/ecma-262/7.0/#sec-regexp.prototype.tostring
-      // for more details.
-      return object == (other + '');
-
-    case mapTag:
-      var convert = mapToArray;
-
-    case setTag:
-      var isPartial = bitmask & PARTIAL_COMPARE_FLAG;
-      convert || (convert = setToArray);
-
-      if (object.size != other.size && !isPartial) {
-        return false;
-      }
-      // Assume cyclic values are equal.
-      var stacked = stack.get(object);
-      if (stacked) {
-        return stacked == other;
-      }
-      bitmask |= UNORDERED_COMPARE_FLAG;
-
-      // Recursively compare objects (susceptible to call stack limits).
-      stack.set(object, other);
-      var result = equalArrays(convert(object), convert(other), equalFunc, customizer, bitmask, stack);
-      stack['delete'](object);
-      return result;
-
-    case symbolTag:
-      if (symbolValueOf) {
-        return symbolValueOf.call(object) == symbolValueOf.call(other);
-      }
-  }
-  return false;
-}
-
-/**
- * A specialized version of `baseIsEqualDeep` for objects with support for
- * partial deep comparisons.
- *
- * @private
- * @param {Object} object The object to compare.
- * @param {Object} other The other object to compare.
- * @param {Function} equalFunc The function to determine equivalents of values.
- * @param {Function} customizer The function to customize comparisons.
- * @param {number} bitmask The bitmask of comparison flags. See `baseIsEqual`
- *  for more details.
- * @param {Object} stack Tracks traversed `object` and `other` objects.
- * @returns {boolean} Returns `true` if the objects are equivalent, else `false`.
- */
-function equalObjects(object, other, equalFunc, customizer, bitmask, stack) {
-  var isPartial = bitmask & PARTIAL_COMPARE_FLAG,
-      objProps = keys(object),
-      objLength = objProps.length,
-      othProps = keys(other),
-      othLength = othProps.length;
-
-  if (objLength != othLength && !isPartial) {
-    return false;
-  }
-  var index = objLength;
-  while (index--) {
-    var key = objProps[index];
-    if (!(isPartial ? key in other : hasOwnProperty.call(other, key))) {
-      return false;
-    }
-  }
-  // Assume cyclic values are equal.
-  var stacked = stack.get(object);
-  if (stacked && stack.get(other)) {
-    return stacked == other;
-  }
-  var result = true;
-  stack.set(object, other);
-  stack.set(other, object);
-
-  var skipCtor = isPartial;
-  while (++index < objLength) {
-    key = objProps[index];
-    var objValue = object[key],
-        othValue = other[key];
-
-    if (customizer) {
-      var compared = isPartial
-        ? customizer(othValue, objValue, key, other, object, stack)
-        : customizer(objValue, othValue, key, object, other, stack);
-    }
-    // Recursively compare objects (susceptible to call stack limits).
-    if (!(compared === undefined
-          ? (objValue === othValue || equalFunc(objValue, othValue, customizer, bitmask, stack))
-          : compared
-        )) {
-      result = false;
-      break;
-    }
-    skipCtor || (skipCtor = key == 'constructor');
-  }
-  if (result && !skipCtor) {
-    var objCtor = object.constructor,
-        othCtor = other.constructor;
-
-    // Non `Object` object instances with different constructors are not equal.
-    if (objCtor != othCtor &&
-        ('constructor' in object && 'constructor' in other) &&
-        !(typeof objCtor == 'function' && objCtor instanceof objCtor &&
-          typeof othCtor == 'function' && othCtor instanceof othCtor)) {
-      result = false;
-    }
-  }
-  stack['delete'](object);
-  stack['delete'](other);
-  return result;
-}
-
-/**
- * Gets the data for `map`.
- *
- * @private
- * @param {Object} map The map to query.
- * @param {string} key The reference key.
- * @returns {*} Returns the map data.
- */
-function getMapData(map, key) {
-  var data = map.__data__;
-  return isKeyable(key)
-    ? data[typeof key == 'string' ? 'string' : 'hash']
-    : data.map;
-}
-
-/**
- * Gets the native function at `key` of `object`.
- *
- * @private
- * @param {Object} object The object to query.
- * @param {string} key The key of the method to get.
- * @returns {*} Returns the function if it's native, else `undefined`.
- */
-function getNative(object, key) {
-  var value = getValue(object, key);
-  return baseIsNative(value) ? value : undefined;
-}
-
-/**
- * Gets the `toStringTag` of `value`.
- *
- * @private
- * @param {*} value The value to query.
- * @returns {string} Returns the `toStringTag`.
- */
-var getTag = baseGetTag;
-
-// Fallback for data views, maps, sets, and weak maps in IE 11,
-// for data views in Edge < 14, and promises in Node.js.
-if ((DataView && getTag(new DataView(new ArrayBuffer(1))) != dataViewTag) ||
-    (Map && getTag(new Map) != mapTag) ||
-    (Promise && getTag(Promise.resolve()) != promiseTag) ||
-    (Set && getTag(new Set) != setTag) ||
-    (WeakMap && getTag(new WeakMap) != weakMapTag)) {
-  getTag = function(value) {
-    var result = objectToString.call(value),
-        Ctor = result == objectTag ? value.constructor : undefined,
-        ctorString = Ctor ? toSource(Ctor) : undefined;
-
-    if (ctorString) {
-      switch (ctorString) {
-        case dataViewCtorString: return dataViewTag;
-        case mapCtorString: return mapTag;
-        case promiseCtorString: return promiseTag;
-        case setCtorString: return setTag;
-        case weakMapCtorString: return weakMapTag;
-      }
-    }
-    return result;
-  };
-}
-
-/**
- * Checks if `value` is a valid array-like index.
- *
- * @private
- * @param {*} value The value to check.
- * @param {number} [length=MAX_SAFE_INTEGER] The upper bounds of a valid index.
- * @returns {boolean} Returns `true` if `value` is a valid index, else `false`.
- */
-function isIndex(value, length) {
-  length = length == null ? MAX_SAFE_INTEGER : length;
-  return !!length &&
-    (typeof value == 'number' || reIsUint.test(value)) &&
-    (value > -1 && value % 1 == 0 && value < length);
-}
-
-/**
- * Checks if `value` is suitable for use as unique object key.
- *
- * @private
- * @param {*} value The value to check.
- * @returns {boolean} Returns `true` if `value` is suitable, else `false`.
- */
-function isKeyable(value) {
-  var type = typeof value;
-  return (type == 'string' || type == 'number' || type == 'symbol' || type == 'boolean')
-    ? (value !== '__proto__')
-    : (value === null);
-}
-
-/**
- * Checks if `func` has its source masked.
- *
- * @private
- * @param {Function} func The function to check.
- * @returns {boolean} Returns `true` if `func` is masked, else `false`.
- */
-function isMasked(func) {
-  return !!maskSrcKey && (maskSrcKey in func);
-}
-
-/**
- * Checks if `value` is likely a prototype object.
- *
- * @private
- * @param {*} value The value to check.
- * @returns {boolean} Returns `true` if `value` is a prototype, else `false`.
- */
-function isPrototype(value) {
-  var Ctor = value && value.constructor,
-      proto = (typeof Ctor == 'function' && Ctor.prototype) || objectProto;
-
-  return value === proto;
-}
-
-/**
- * Converts `func` to its source code.
- *
- * @private
- * @param {Function} func The function to process.
- * @returns {string} Returns the source code.
- */
-function toSource(func) {
-  if (func != null) {
-    try {
-      return funcToString.call(func);
-    } catch (e) {}
-    try {
-      return (func + '');
-    } catch (e) {}
-  }
-  return '';
-}
-
-/**
- * Performs a
- * [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero)
- * comparison between two values to determine if they are equivalent.
- *
- * @static
- * @memberOf _
- * @since 4.0.0
- * @category Lang
- * @param {*} value The value to compare.
- * @param {*} other The other value to compare.
- * @returns {boolean} Returns `true` if the values are equivalent, else `false`.
- * @example
- *
- * var object = { 'a': 1 };
- * var other = { 'a': 1 };
- *
- * _.eq(object, object);
- * // => true
- *
- * _.eq(object, other);
- * // => false
- *
- * _.eq('a', 'a');
- * // => true
- *
- * _.eq('a', Object('a'));
- * // => false
- *
- * _.eq(NaN, NaN);
- * // => true
- */
-function eq(value, other) {
-  return value === other || (value !== value && other !== other);
-}
-
-/**
- * Checks if `value` is likely an `arguments` object.
- *
- * @static
- * @memberOf _
- * @since 0.1.0
- * @category Lang
- * @param {*} value The value to check.
- * @returns {boolean} Returns `true` if `value` is an `arguments` object,
- *  else `false`.
- * @example
- *
- * _.isArguments(function() { return arguments; }());
- * // => true
- *
- * _.isArguments([1, 2, 3]);
- * // => false
- */
-function isArguments(value) {
-  // Safari 8.1 makes `arguments.callee` enumerable in strict mode.
-  return isArrayLikeObject(value) && hasOwnProperty.call(value, 'callee') &&
-    (!propertyIsEnumerable.call(value, 'callee') || objectToString.call(value) == argsTag);
-}
-
-/**
- * Checks if `value` is classified as an `Array` object.
- *
- * @static
- * @memberOf _
- * @since 0.1.0
- * @category Lang
- * @param {*} value The value to check.
- * @returns {boolean} Returns `true` if `value` is an array, else `false`.
- * @example
- *
- * _.isArray([1, 2, 3]);
- * // => true
- *
- * _.isArray(document.body.children);
- * // => false
- *
- * _.isArray('abc');
- * // => false
- *
- * _.isArray(_.noop);
- * // => false
- */
-var isArray = Array.isArray;
-
-/**
- * Checks if `value` is array-like. A value is considered array-like if it's
- * not a function and has a `value.length` that's an integer greater than or
- * equal to `0` and less than or equal to `Number.MAX_SAFE_INTEGER`.
- *
- * @static
- * @memberOf _
- * @since 4.0.0
- * @category Lang
- * @param {*} value The value to check.
- * @returns {boolean} Returns `true` if `value` is array-like, else `false`.
- * @example
- *
- * _.isArrayLike([1, 2, 3]);
- * // => true
- *
- * _.isArrayLike(document.body.children);
- * // => true
- *
- * _.isArrayLike('abc');
- * // => true
- *
- * _.isArrayLike(_.noop);
- * // => false
- */
-function isArrayLike(value) {
-  return value != null && isLength(value.length) && !isFunction(value);
-}
-
-/**
- * This method is like `_.isArrayLike` except that it also checks if `value`
- * is an object.
- *
- * @static
- * @memberOf _
- * @since 4.0.0
- * @category Lang
- * @param {*} value The value to check.
- * @returns {boolean} Returns `true` if `value` is an array-like object,
- *  else `false`.
- * @example
- *
- * _.isArrayLikeObject([1, 2, 3]);
- * // => true
- *
- * _.isArrayLikeObject(document.body.children);
- * // => true
- *
- * _.isArrayLikeObject('abc');
- * // => false
- *
- * _.isArrayLikeObject(_.noop);
- * // => false
- */
-function isArrayLikeObject(value) {
-  return isObjectLike(value) && isArrayLike(value);
-}
-
-/**
- * Performs a deep comparison between two values to determine if they are
- * equivalent.
- *
- * **Note:** This method supports comparing arrays, array buffers, booleans,
- * date objects, error objects, maps, numbers, `Object` objects, regexes,
- * sets, strings, symbols, and typed arrays. `Object` objects are compared
- * by their own, not inherited, enumerable properties. Functions and DOM
- * nodes are **not** supported.
- *
- * @static
- * @memberOf _
- * @since 0.1.0
- * @category Lang
- * @param {*} value The value to compare.
- * @param {*} other The other value to compare.
- * @returns {boolean} Returns `true` if the values are equivalent, else `false`.
- * @example
- *
- * var object = { 'a': 1 };
- * var other = { 'a': 1 };
- *
- * _.isEqual(object, other);
- * // => true
- *
- * object === other;
- * // => false
- */
-function isEqual(value, other) {
-  return baseIsEqual(value, other);
-}
-
-/**
- * Checks if `value` is classified as a `Function` object.
- *
- * @static
- * @memberOf _
- * @since 0.1.0
- * @category Lang
- * @param {*} value The value to check.
- * @returns {boolean} Returns `true` if `value` is a function, else `false`.
- * @example
- *
- * _.isFunction(_);
- * // => true
- *
- * _.isFunction(/abc/);
- * // => false
- */
-function isFunction(value) {
-  // The use of `Object#toString` avoids issues with the `typeof` operator
-  // in Safari 8-9 which returns 'object' for typed array and other constructors.
-  var tag = isObject(value) ? objectToString.call(value) : '';
-  return tag == funcTag || tag == genTag;
-}
-
-/**
- * Checks if `value` is a valid array-like length.
- *
- * **Note:** This method is loosely based on
- * [`ToLength`](http://ecma-international.org/ecma-262/7.0/#sec-tolength).
- *
- * @static
- * @memberOf _
- * @since 4.0.0
- * @category Lang
- * @param {*} value The value to check.
- * @returns {boolean} Returns `true` if `value` is a valid length, else `false`.
- * @example
- *
- * _.isLength(3);
- * // => true
- *
- * _.isLength(Number.MIN_VALUE);
- * // => false
- *
- * _.isLength(Infinity);
- * // => false
- *
- * _.isLength('3');
- * // => false
- */
-function isLength(value) {
-  return typeof value == 'number' &&
-    value > -1 && value % 1 == 0 && value <= MAX_SAFE_INTEGER;
-}
-
-/**
- * Checks if `value` is the
- * [language type](http://www.ecma-international.org/ecma-262/7.0/#sec-ecmascript-language-types)
- * of `Object`. (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
- *
- * @static
- * @memberOf _
- * @since 0.1.0
- * @category Lang
- * @param {*} value The value to check.
- * @returns {boolean} Returns `true` if `value` is an object, else `false`.
- * @example
- *
- * _.isObject({});
- * // => true
- *
- * _.isObject([1, 2, 3]);
- * // => true
- *
- * _.isObject(_.noop);
- * // => true
- *
- * _.isObject(null);
- * // => false
- */
-function isObject(value) {
-  var type = typeof value;
-  return !!value && (type == 'object' || type == 'function');
-}
-
-/**
- * Checks if `value` is object-like. A value is object-like if it's not `null`
- * and has a `typeof` result of "object".
- *
- * @static
- * @memberOf _
- * @since 4.0.0
- * @category Lang
- * @param {*} value The value to check.
- * @returns {boolean} Returns `true` if `value` is object-like, else `false`.
- * @example
- *
- * _.isObjectLike({});
- * // => true
- *
- * _.isObjectLike([1, 2, 3]);
- * // => true
- *
- * _.isObjectLike(_.noop);
- * // => false
- *
- * _.isObjectLike(null);
- * // => false
- */
-function isObjectLike(value) {
-  return !!value && typeof value == 'object';
-}
-
-/**
- * Checks if `value` is classified as a typed array.
- *
- * @static
- * @memberOf _
- * @since 3.0.0
- * @category Lang
- * @param {*} value The value to check.
- * @returns {boolean} Returns `true` if `value` is a typed array, else `false`.
- * @example
- *
- * _.isTypedArray(new Uint8Array);
- * // => true
- *
- * _.isTypedArray([]);
- * // => false
- */
-var isTypedArray = nodeIsTypedArray ? baseUnary(nodeIsTypedArray) : baseIsTypedArray;
-
-/**
- * Creates an array of the own enumerable property names of `object`.
- *
- * **Note:** Non-object values are coerced to objects. See the
- * [ES spec](http://ecma-international.org/ecma-262/7.0/#sec-object.keys)
- * for more details.
- *
- * @static
- * @since 0.1.0
- * @memberOf _
- * @category Object
- * @param {Object} object The object to query.
- * @returns {Array} Returns the array of property names.
- * @example
- *
- * function Foo() {
- *   this.a = 1;
- *   this.b = 2;
- * }
- *
- * Foo.prototype.c = 3;
- *
- * _.keys(new Foo);
- * // => ['a', 'b'] (iteration order is not guaranteed)
- *
- * _.keys('hi');
- * // => ['0', '1']
- */
-function keys(object) {
-  return isArrayLike(object) ? arrayLikeKeys(object) : baseKeys(object);
-}
-
-module.exports = isEqual;
diff --git a/src/common/rangeset.ts b/src/common/rangeset.ts
index 51cbf318..82e0780e 100644
--- a/src/common/rangeset.ts
+++ b/src/common/rangeset.ts
@@ -35,7 +35,7 @@ class RangeSet {
   }
 
   addRange(start: number, end: number) {
-    assert(start <= end, `invalid range ${start} <= ${end}`)
+    assert.ok(start <= end, `invalid range ${start} <= ${end}`)
     this.ranges = mergeIntervals(this.ranges.concat([[start, end]]))
   }
 
diff --git a/src/common/schema-validator.ts b/src/common/schema-validator.ts
index 5985c7bd..4d82bdc8 100644
--- a/src/common/schema-validator.ts
+++ b/src/common/schema-validator.ts
@@ -121,7 +121,7 @@ function loadSchemas() {
   ]
   const titles = schemas.map(schema => schema.title)
   const duplicates = _.keys(_.pickBy(_.countBy(titles), count => count > 1))
-  assert(duplicates.length === 0, 'Duplicate schemas for: ' + duplicates)
+  assert.ok(duplicates.length === 0, 'Duplicate schemas for: ' + duplicates)
   const validator = new Validator()
   // Register custom format validators that ignore undefined instances
   // since jsonschema will still call the format validator on a missing
diff --git a/src/common/utils.ts b/src/common/utils.ts
index d0a83fbf..470262f9 100644
--- a/src/common/utils.ts
+++ b/src/common/utils.ts
@@ -17,7 +17,7 @@ function dropsToXrp(drops: string | BigNumber): string {
   if (typeof drops === 'string') {
     if (!drops.match(/^-?[0-9]*\.?[0-9]*$/)) {
       throw new ValidationError(`dropsToXrp: invalid value '${drops}',` +
-        ` should be a number matching (^-?[0-9]*.?[0-9]*$).`)
+        ` should be a number matching (^-?[0-9]*\\.?[0-9]*$).`)
     } else if (drops === '.') {
       throw new ValidationError(`dropsToXrp: invalid value '${drops}',` +
         ` should be a BigNumber or string-encoded number.`)
@@ -51,7 +51,7 @@ function xrpToDrops(xrp: string | BigNumber): string {
   if (typeof xrp === 'string') {
     if (!xrp.match(/^-?[0-9]*\.?[0-9]*$/)) {
       throw new ValidationError(`xrpToDrops: invalid value '${xrp}',` +
-        ` should be a number matching (^-?[0-9]*.?[0-9]*$).`)
+        ` should be a number matching (^-?[0-9]*\\.?[0-9]*$).`)
     } else if (xrp === '.') {
       throw new ValidationError(`xrpToDrops: invalid value '${xrp}',` +
         ` should be a BigNumber or string-encoded number.`)
diff --git a/src/ledger/parse/cancellation.ts b/src/ledger/parse/cancellation.ts
index e14c20bc..4ca537bb 100644
--- a/src/ledger/parse/cancellation.ts
+++ b/src/ledger/parse/cancellation.ts
@@ -1,7 +1,7 @@
 import * as assert from 'assert'
 
 function parseOrderCancellation(tx: any): object {
-  assert(tx.TransactionType === 'OfferCancel')
+  assert.ok(tx.TransactionType === 'OfferCancel')
   return {
     orderSequence: tx.OfferSequence
   }
diff --git a/src/ledger/parse/check-cancel.ts b/src/ledger/parse/check-cancel.ts
index 437944bb..edd8f5b0 100644
--- a/src/ledger/parse/check-cancel.ts
+++ b/src/ledger/parse/check-cancel.ts
@@ -8,7 +8,7 @@ export type FormattedCheckCancel = {
 }
 
 function parseCheckCancel(tx: any): FormattedCheckCancel {
-  assert(tx.TransactionType === 'CheckCancel')
+  assert.ok(tx.TransactionType === 'CheckCancel')
 
   return removeUndefined({
     checkID: tx.CheckID
diff --git a/src/ledger/parse/check-cash.ts b/src/ledger/parse/check-cash.ts
index 211bf046..b2a7db46 100644
--- a/src/ledger/parse/check-cash.ts
+++ b/src/ledger/parse/check-cash.ts
@@ -23,7 +23,7 @@ export type FormattedCheckCash = {
 }
 
 function parseCheckCash(tx: any): FormattedCheckCash {
-  assert(tx.TransactionType === 'CheckCash')
+  assert.ok(tx.TransactionType === 'CheckCash')
 
   return removeUndefined({
     checkID: tx.CheckID,
diff --git a/src/ledger/parse/check-create.ts b/src/ledger/parse/check-create.ts
index e468add9..6a08edee 100644
--- a/src/ledger/parse/check-create.ts
+++ b/src/ledger/parse/check-create.ts
@@ -24,7 +24,7 @@ export type FormattedCheckCreate = {
 }
 
 function parseCheckCreate(tx: any): FormattedCheckCreate {
-  assert(tx.TransactionType === 'CheckCreate')
+  assert.ok(tx.TransactionType === 'CheckCreate')
 
   return removeUndefined({
     destination: tx.Destination,
diff --git a/src/ledger/parse/deposit-preauth.ts b/src/ledger/parse/deposit-preauth.ts
index 63b4dc84..eac29691 100644
--- a/src/ledger/parse/deposit-preauth.ts
+++ b/src/ledger/parse/deposit-preauth.ts
@@ -10,7 +10,7 @@ export type FormattedDepositPreauth = {
 }
 
 function parseDepositPreauth(tx: any): FormattedDepositPreauth {
-  assert(tx.TransactionType === 'DepositPreauth')
+  assert.ok(tx.TransactionType === 'DepositPreauth')
 
   return removeUndefined({
     authorize: tx.Authorize,
diff --git a/src/ledger/parse/escrow-cancellation.ts b/src/ledger/parse/escrow-cancellation.ts
index 9abd61f5..7d1bcddf 100644
--- a/src/ledger/parse/escrow-cancellation.ts
+++ b/src/ledger/parse/escrow-cancellation.ts
@@ -3,7 +3,7 @@ import {parseMemos} from './utils'
 import {removeUndefined} from '../../common'
 
 function parseEscrowCancellation(tx: any): object {
-  assert(tx.TransactionType === 'EscrowCancel')
+  assert.ok(tx.TransactionType === 'EscrowCancel')
 
   return removeUndefined({
     memos: parseMemos(tx),
diff --git a/src/ledger/parse/escrow-creation.ts b/src/ledger/parse/escrow-creation.ts
index d50dc09e..cc601bd2 100644
--- a/src/ledger/parse/escrow-creation.ts
+++ b/src/ledger/parse/escrow-creation.ts
@@ -4,7 +4,7 @@ import {parseTimestamp, parseMemos} from './utils'
 import {removeUndefined} from '../../common'
 
 function parseEscrowCreation(tx: any): object {
-  assert(tx.TransactionType === 'EscrowCreate')
+  assert.ok(tx.TransactionType === 'EscrowCreate')
 
   return removeUndefined({
     amount: parseAmount(tx.Amount).value,
diff --git a/src/ledger/parse/escrow-execution.ts b/src/ledger/parse/escrow-execution.ts
index a02d4e7a..c4adc707 100644
--- a/src/ledger/parse/escrow-execution.ts
+++ b/src/ledger/parse/escrow-execution.ts
@@ -3,7 +3,7 @@ import {parseMemos} from './utils'
 import {removeUndefined} from '../../common'
 
 function parseEscrowExecution(tx: any): object {
-  assert(tx.TransactionType === 'EscrowFinish')
+  assert.ok(tx.TransactionType === 'EscrowFinish')
 
   return removeUndefined({
     memos: parseMemos(tx),
diff --git a/src/ledger/parse/order.ts b/src/ledger/parse/order.ts
index 3a086505..8a16e8bf 100644
--- a/src/ledger/parse/order.ts
+++ b/src/ledger/parse/order.ts
@@ -10,7 +10,7 @@ import {
 const flags = txFlags.OfferCreate
 
 function parseOrder(tx: OfferCreateTransaction): FormattedOrderSpecification {
-  assert(tx.TransactionType === 'OfferCreate')
+  assert.ok(tx.TransactionType === 'OfferCreate')
 
   const direction = (tx.Flags & flags.Sell) === 0 ? 'buy' : 'sell'
   const takerGetsAmount = parseAmount(tx.TakerGets)
diff --git a/src/ledger/parse/payment-channel-claim.ts b/src/ledger/parse/payment-channel-claim.ts
index 1883a40c..bede3dd9 100644
--- a/src/ledger/parse/payment-channel-claim.ts
+++ b/src/ledger/parse/payment-channel-claim.ts
@@ -4,7 +4,7 @@ import parseAmount from './amount'
 const claimFlags = txFlags.PaymentChannelClaim
 
 function parsePaymentChannelClaim(tx: any): object {
-  assert(tx.TransactionType === 'PaymentChannelClaim')
+  assert.ok(tx.TransactionType === 'PaymentChannelClaim')
 
   return removeUndefined({
     channel: tx.Channel,
diff --git a/src/ledger/parse/payment-channel-create.ts b/src/ledger/parse/payment-channel-create.ts
index a3feab3e..f0943e28 100644
--- a/src/ledger/parse/payment-channel-create.ts
+++ b/src/ledger/parse/payment-channel-create.ts
@@ -4,7 +4,7 @@ import {removeUndefined} from '../../common'
 import parseAmount from './amount'
 
 function parsePaymentChannelCreate(tx: any): object {
-  assert(tx.TransactionType === 'PaymentChannelCreate')
+  assert.ok(tx.TransactionType === 'PaymentChannelCreate')
 
   return removeUndefined({
     amount: parseAmount(tx.Amount).value,
diff --git a/src/ledger/parse/payment-channel-fund.ts b/src/ledger/parse/payment-channel-fund.ts
index 54b23f17..2503978b 100644
--- a/src/ledger/parse/payment-channel-fund.ts
+++ b/src/ledger/parse/payment-channel-fund.ts
@@ -4,7 +4,7 @@ import {removeUndefined} from '../../common'
 import parseAmount from './amount'
 
 function parsePaymentChannelFund(tx: any): object {
-  assert(tx.TransactionType === 'PaymentChannelFund')
+  assert.ok(tx.TransactionType === 'PaymentChannelFund')
 
   return removeUndefined({
     channel: tx.Channel,
diff --git a/src/ledger/parse/payment.ts b/src/ledger/parse/payment.ts
index c502c292..5089bf90 100644
--- a/src/ledger/parse/payment.ts
+++ b/src/ledger/parse/payment.ts
@@ -19,7 +19,7 @@ function removeGenericCounterparty(amount, address) {
 
 // Payment specification
 function parsePayment(tx: any): object {
-  assert(tx.TransactionType === 'Payment')
+  assert.ok(tx.TransactionType === 'Payment')
 
   const source = {
     address: tx.Account,
diff --git a/src/ledger/parse/settings.ts b/src/ledger/parse/settings.ts
index ecbc7e2e..44f3b100 100644
--- a/src/ledger/parse/settings.ts
+++ b/src/ledger/parse/settings.ts
@@ -7,7 +7,7 @@ import parseFields from './fields'
 function getAccountRootModifiedNode(tx: any) {
   const modifiedNodes = tx.meta.AffectedNodes.filter(node =>
     node.ModifiedNode.LedgerEntryType === 'AccountRoot')
-  assert(modifiedNodes.length === 1)
+  assert.ok(modifiedNodes.length === 1)
   return modifiedNodes[0].ModifiedNode
 }
 
@@ -51,7 +51,7 @@ function parseFlags(tx: any): any {
 
 function parseSettings(tx: any) {
   const txType = tx.TransactionType
-  assert(txType === 'AccountSet' || txType === 'SetRegularKey' ||
+  assert.ok(txType === 'AccountSet' || txType === 'SetRegularKey' ||
          txType === 'SignerListSet')
 
   return _.assign({}, parseFlags(tx), parseFields(tx))
diff --git a/src/ledger/parse/trustline.ts b/src/ledger/parse/trustline.ts
index 6225ab18..ee0982c1 100644
--- a/src/ledger/parse/trustline.ts
+++ b/src/ledger/parse/trustline.ts
@@ -14,7 +14,7 @@ function parseFlag(flagsValue, trueValue, falseValue) {
 }
 
 function parseTrustline(tx: any): object {
-  assert(tx.TransactionType === 'TrustSet')
+  assert.ok(tx.TransactionType === 'TrustSet')
 
   return removeUndefined({
     limit: tx.LimitAmount.value,
diff --git a/src/ledger/parse/utils.ts b/src/ledger/parse/utils.ts
index 771ebb70..1f53504c 100644
--- a/src/ledger/parse/utils.ts
+++ b/src/ledger/parse/utils.ts
@@ -1,5 +1,5 @@
 import * as _ from 'lodash'
-import transactionParser = require('ripple-lib-transactionparser')
+import transactionParser from 'ripple-lib-transactionparser'
 import BigNumber from 'bignumber.js'
 import * as common from '../../common'
 import parseAmount from './amount'
diff --git a/src/ledger/transactions.ts b/src/ledger/transactions.ts
index 0ad5b8ee..9ad9ba99 100644
--- a/src/ledger/transactions.ts
+++ b/src/ledger/transactions.ts
@@ -1,5 +1,5 @@
 import * as _ from 'lodash'
-import binary = require('ripple-binary-codec')
+import binary from 'ripple-binary-codec';
 import {computeTransactionHash} from '../common/hashes'
 import * as utils from './utils'
 import parseTransaction from './parse/transaction'
diff --git a/src/ledger/utils.ts b/src/ledger/utils.ts
index f9dae255..430b85ee 100644
--- a/src/ledger/utils.ts
+++ b/src/ledger/utils.ts
@@ -4,7 +4,7 @@ import * as common from '../common'
 import {Connection} from '../common'
 import {FormattedTransactionType} from '../transaction/types'
 import {Issue} from '../common/types/objects'
-import {RippleAPI} from '..'
+import {RippleAPI} from '..' 
 
 export type RecursiveData = {
   marker: string,
@@ -14,7 +14,7 @@ export type RecursiveData = {
 export type Getter = (marker?: string, limit?: number) => Promise<RecursiveData>
 
 function clamp(value: number, min: number, max: number): number {
-  assert(min <= max, 'Illegal clamp bounds')
+  assert.ok(min <= max, 'Illegal clamp bounds')
   return Math.min(Math.max(value, min), max)
 }
 
diff --git a/src/offline/generate-address.ts b/src/offline/generate-address.ts
index 554874db..c2940fdb 100644
--- a/src/offline/generate-address.ts
+++ b/src/offline/generate-address.ts
@@ -1,4 +1,4 @@
-import keypairs = require('ripple-keypairs')
+import keypairs from 'ripple-keypairs'
 import * as common from '../common'
 const {errors, validate} = common
 
diff --git a/src/offline/sign-payment-channel-claim.ts b/src/offline/sign-payment-channel-claim.ts
index fd133af5..015396af 100644
--- a/src/offline/sign-payment-channel-claim.ts
+++ b/src/offline/sign-payment-channel-claim.ts
@@ -1,6 +1,6 @@
 import * as common from '../common'
-import keypairs = require('ripple-keypairs')
-import binary = require('ripple-binary-codec')
+import keypairs from 'ripple-keypairs'
+import binary from 'ripple-binary-codec'
 const {validate, xrpToDrops} = common
 
 function signPaymentChannelClaim(channel: string, amount: string,
diff --git a/src/offline/verify-payment-channel-claim.ts b/src/offline/verify-payment-channel-claim.ts
index 93b9801e..a34f215c 100644
--- a/src/offline/verify-payment-channel-claim.ts
+++ b/src/offline/verify-payment-channel-claim.ts
@@ -1,5 +1,5 @@
-import keypairs = require('ripple-keypairs')
-import binary = require('ripple-binary-codec')
+import keypairs from 'ripple-keypairs'
+import binary from 'ripple-binary-codec'
 import {validate, xrpToDrops} from '../common'
 
 function verifyPaymentChannelClaim(channel: string, amount: string,
diff --git a/src/transaction/combine.ts b/src/transaction/combine.ts
index e4ac491e..e4a1a02f 100644
--- a/src/transaction/combine.ts
+++ b/src/transaction/combine.ts
@@ -1,5 +1,5 @@
 import * as _ from 'lodash'
-import binary = require('ripple-binary-codec')
+import binary from 'ripple-binary-codec'
 import * as utils from './utils'
 import BigNumber from 'bignumber.js'
 import {decodeAddress} from 'ripple-address-codec'
diff --git a/src/transaction/settings.ts b/src/transaction/settings.ts
index 9e17da86..c7d169cf 100644
--- a/src/transaction/settings.ts
+++ b/src/transaction/settings.ts
@@ -10,7 +10,7 @@ import {RippleAPI} from '..'
 
 function setTransactionFlags(txJSON: utils.TransactionJSON, values: FormattedSettings) {
   const keys = Object.keys(values)
-  assert(keys.length === 1, 'ERROR: can only set one setting per transaction')
+  assert.ok(keys.length === 1, 'ERROR: can only set one setting per transaction')
   const flagName = keys[0]
   const value = values[flagName]
   const index = AccountFlagIndices[flagName]
diff --git a/src/transaction/sign.ts b/src/transaction/sign.ts
index eeac0e8f..e3a6a112 100644
--- a/src/transaction/sign.ts
+++ b/src/transaction/sign.ts
@@ -1,13 +1,13 @@
-import * as isEqual from '../common/js/lodash.isequal'
+import isEqual from 'lodash.isequal'
 import * as utils from './utils'
-import keypairs = require('ripple-keypairs')
-import binaryCodec = require('ripple-binary-codec')
+import keypairs from 'ripple-keypairs'
+import binaryCodec from 'ripple-binary-codec'
 import {computeBinaryTransactionHash} from '../common/hashes'
 import {SignOptions, KeyPair} from './types'
 import {BigNumber} from 'bignumber.js'
 import {xrpToDrops} from '../common'
 import {RippleAPI} from '..'
-const validate = utils.common.validate
+const validate = utils.common.validate 
 
 function computeSignature(tx: object, privateKey: string, signAs?: string) {
   const signingData = signAs
diff --git a/tsconfig-base.json b/tsconfig-base.json
index 0c222676..5d968f83 100644
--- a/tsconfig-base.json
+++ b/tsconfig-base.json
@@ -1,26 +1,22 @@
 {
   "compilerOptions": {
     "pretty": true,
-    "lib": [
-      "es2017"
-    ],
-    "target": "es6",
+    "target": "es2017",
+    "module": "commonjs",
+    "moduleResolution": "node",
 
     "declaration": true,
     "declarationMap": true /* Added 2019-04-13 */,
     "sourceMap": true,
-    "noEmitOnError": true /* Added 2019-04-13 */,
 
+    "strict": true /* Enable all strict type-checking options. */,
     "strictNullChecks": false,
     "noImplicitAny": false,
     "noUnusedLocals": true,
     "noUnusedParameters": true,
     "removeComments": true,
-    "strict": true /* Enable all strict type-checking options. */,
     "preserveConstEnums": false,
-
-    "module": "commonjs",
-    "moduleResolution": "node",
+    "esModuleInterop": true,
     "suppressImplicitAnyIndexErrors": false
   }
 }
diff --git a/yarn.lock b/yarn.lock
index b10dbfe8..b15ff51d 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3012,6 +3012,17 @@ lodash.unescape@4.0.1:
   resolved "https://registry.yarnpkg.com/lodash.unescape/-/lodash.unescape-4.0.1.tgz#bf2249886ce514cda112fae9218cdc065211fc9c"
   integrity sha1-vyJJiGzlFM2hEvrpIYzcBlIR/Jw=
 
+lodash.isequal@^4.5.0:
+  version "4.5.0"
+  resolved "https://registry.yarnpkg.com/lodash.isequal/-/lodash.isequal-4.5.0.tgz#415c4478f2bcc30120c22ce10ed3226f7d3e18e0"
+  integrity sha1-QVxEePK8wwEgwizhDtMib30+GOA=
+
+lodash@^4.17.11, lodash@^4.17.4:
+  version "4.17.13"
+  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.13.tgz#0bdc3a6adc873d2f4e0c4bac285df91b64fc7b93"
+  integrity sha512-vm3/XWXfWtRua0FkUyEHBZy8kCPjErNBT9fJx8Zvs+U6zjqPbTUOpkaoum3O5uiA8sm+yNMHXfYkTUHFoMxFNA==
+
+
 lodash@^4.17.11, lodash@^4.17.12, lodash@^4.17.13, lodash@^4.17.14, lodash@^4.17.15, lodash@^4.17.4:
   version "4.17.15"
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.15.tgz#b447f6670a0455bbfeedd11392eff330ea097548"