var clone = (function() {
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'use strict';
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/**
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* Clones (copies) an Object using deep copying.
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*
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* This function supports circular references by default, but if you are certain
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* there are no circular references in your object, you can save some CPU time
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* by calling clone(obj, false).
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*
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* Caution: if `circular` is false and `parent` contains circular references,
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* your program may enter an infinite loop and crash.
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*
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* @param `parent` - the object to be cloned
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* @param `circular` - set to true if the object to be cloned may contain
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* circular references. (optional - true by default)
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* @param `depth` - set to a number if the object is only to be cloned to
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* a particular depth. (optional - defaults to Infinity)
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* @param `prototype` - sets the prototype to be used when cloning an object.
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* (optional - defaults to parent prototype).
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*/
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function clone(parent, circular, depth, prototype) {
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var filter;
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if (typeof circular === 'object') {
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depth = circular.depth;
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prototype = circular.prototype;
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filter = circular.filter;
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circular = circular.circular
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}
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// maintain two arrays for circular references, where corresponding parents
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// and children have the same index
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var allParents = [];
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var allChildren = [];
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var useBuffer = typeof Buffer != 'undefined';
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if (typeof circular == 'undefined')
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circular = true;
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if (typeof depth == 'undefined')
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depth = Infinity;
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// recurse this function so we don't reset allParents and allChildren
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function _clone(parent, depth) {
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// cloning null always returns null
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if (parent === null)
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return null;
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if (depth == 0)
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return parent;
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var child;
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var proto;
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if (typeof parent != 'object') {
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return parent;
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}
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if (clone.__isArray(parent)) {
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child = [];
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} else if (clone.__isRegExp(parent)) {
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child = new RegExp(parent.source, __getRegExpFlags(parent));
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if (parent.lastIndex) child.lastIndex = parent.lastIndex;
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} else if (clone.__isDate(parent)) {
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child = new Date(parent.getTime());
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} else if (useBuffer && Buffer.isBuffer(parent)) {
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if (Buffer.allocUnsafe) {
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// Node.js >= 4.5.0
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child = Buffer.allocUnsafe(parent.length);
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} else {
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// Older Node.js versions
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child = new Buffer(parent.length);
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}
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parent.copy(child);
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return child;
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} else {
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if (typeof prototype == 'undefined') {
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proto = Object.getPrototypeOf(parent);
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child = Object.create(proto);
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}
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else {
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child = Object.create(prototype);
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proto = prototype;
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}
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}
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if (circular) {
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var index = allParents.indexOf(parent);
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if (index != -1) {
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return allChildren[index];
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}
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allParents.push(parent);
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allChildren.push(child);
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}
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for (var i in parent) {
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var attrs;
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if (proto) {
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attrs = Object.getOwnPropertyDescriptor(proto, i);
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}
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if (attrs && attrs.set == null) {
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continue;
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}
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child[i] = _clone(parent[i], depth - 1);
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}
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return child;
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}
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return _clone(parent, depth);
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}
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/**
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* Simple flat clone using prototype, accepts only objects, usefull for property
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* override on FLAT configuration object (no nested props).
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*
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* USE WITH CAUTION! This may not behave as you wish if you do not know how this
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* works.
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*/
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clone.clonePrototype = function clonePrototype(parent) {
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if (parent === null)
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return null;
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var c = function () {};
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c.prototype = parent;
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return new c();
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};
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// private utility functions
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function __objToStr(o) {
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return Object.prototype.toString.call(o);
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};
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clone.__objToStr = __objToStr;
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function __isDate(o) {
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return typeof o === 'object' && __objToStr(o) === '[object Date]';
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};
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clone.__isDate = __isDate;
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function __isArray(o) {
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return typeof o === 'object' && __objToStr(o) === '[object Array]';
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};
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clone.__isArray = __isArray;
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function __isRegExp(o) {
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return typeof o === 'object' && __objToStr(o) === '[object RegExp]';
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};
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clone.__isRegExp = __isRegExp;
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function __getRegExpFlags(re) {
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var flags = '';
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if (re.global) flags += 'g';
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if (re.ignoreCase) flags += 'i';
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if (re.multiline) flags += 'm';
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return flags;
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};
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clone.__getRegExpFlags = __getRegExpFlags;
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return clone;
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})();
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if (typeof module === 'object' && module.exports) {
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module.exports = clone;
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}
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