node_modules/jszip/node_modules/core-js/library/modules/_collection.js

'use strict';
var global         = require('./_global')
  , $export        = require('./_export')
  , meta           = require('./_meta')
  , fails          = require('./_fails')
  , hide           = require('./_hide')
  , redefineAll    = require('./_redefine-all')
  , forOf          = require('./_for-of')
  , anInstance     = require('./_an-instance')
  , isObject       = require('./_is-object')
  , setToStringTag = require('./_set-to-string-tag')
  , dP             = require('./_object-dp').f
  , each           = require('./_array-methods')(0)
  , DESCRIPTORS    = require('./_descriptors');

module.exports = function(NAME, wrapper, methods, common, IS_MAP, IS_WEAK){
  var Base  = global[NAME]
    , C     = Base
    , ADDER = IS_MAP ? 'set' : 'add'
    , proto = C && C.prototype
    , O     = {};
  if(!DESCRIPTORS || typeof C != 'function' || !(IS_WEAK || proto.forEach && !fails(function(){
    new C().entries().next();
  }))){
    // create collection constructor
    C = common.getConstructor(wrapper, NAME, IS_MAP, ADDER);
    redefineAll(C.prototype, methods);
    meta.NEED = true;
  } else {
    C = wrapper(function(target, iterable){
      anInstance(target, C, NAME, '_c');
      target._c = new Base;
      if(iterable != undefined)forOf(iterable, IS_MAP, target[ADDER], target);
    });
    each('add,clear,delete,forEach,get,has,set,keys,values,entries,toJSON'.split(','),function(KEY){
      var IS_ADDER = KEY == 'add' || KEY == 'set';
      if(KEY in proto && !(IS_WEAK && KEY == 'clear'))hide(C.prototype, KEY, function(a, b){
        anInstance(this, C, KEY);
        if(!IS_ADDER && IS_WEAK && !isObject(a))return KEY == 'get' ? undefined : false;
        var result = this._c[KEY](a === 0 ? 0 : a, b);
        return IS_ADDER ? this : result;
      });
    });
    if('size' in proto)dP(C.prototype, 'size', {
      get: function(){
        return this._c.size;
      }
    });
  }

  setToStringTag(C, NAME);

  O[NAME] = C;
  $export($export.G + $export.W + $export.F, O);

  if(!IS_WEAK)common.setStrong(C, NAME, IS_MAP);

  return C;
};