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Standard library
There is a newer version: 3.39.0
'use strict';
var global = require('../internals/global');
var apply = require('../internals/function-apply');
var uncurryThis = require('../internals/function-uncurry-this-clause');
var isCallable = require('../internals/is-callable');
var getOwnPropertyDescriptor = require('../internals/object-get-own-property-descriptor').f;
var isForced = require('../internals/is-forced');
var path = require('../internals/path');
var bind = require('../internals/function-bind-context');
var createNonEnumerableProperty = require('../internals/create-non-enumerable-property');
var hasOwn = require('../internals/has-own-property');

var wrapConstructor = function (NativeConstructor) {
  var Wrapper = function (a, b, c) {
    if (this instanceof Wrapper) {
      switch (arguments.length) {
        case 0: return new NativeConstructor();
        case 1: return new NativeConstructor(a);
        case 2: return new NativeConstructor(a, b);
      } return new NativeConstructor(a, b, c);
    } return apply(NativeConstructor, this, arguments);
  };
  Wrapper.prototype = NativeConstructor.prototype;
  return Wrapper;
};

/*
  options.target         - name of the target object
  options.global         - target is the global object
  options.stat           - export as static methods of target
  options.proto          - export as prototype methods of target
  options.real           - real prototype method for the `pure` version
  options.forced         - export even if the native feature is available
  options.bind           - bind methods to the target, required for the `pure` version
  options.wrap           - wrap constructors to preventing global pollution, required for the `pure` version
  options.unsafe         - use the simple assignment of property instead of delete + defineProperty
  options.sham           - add a flag to not completely full polyfills
  options.enumerable     - export as enumerable property
  options.dontCallGetSet - prevent calling a getter on target
  options.name           - the .name of the function if it does not match the key
*/
module.exports = function (options, source) {
  var TARGET = options.target;
  var GLOBAL = options.global;
  var STATIC = options.stat;
  var PROTO = options.proto;

  var nativeSource = GLOBAL ? global : STATIC ? global[TARGET] : (global[TARGET] || {}).prototype;

  var target = GLOBAL ? path : path[TARGET] || createNonEnumerableProperty(path, TARGET, {})[TARGET];
  var targetPrototype = target.prototype;

  var FORCED, USE_NATIVE, VIRTUAL_PROTOTYPE;
  var key, sourceProperty, targetProperty, nativeProperty, resultProperty, descriptor;

  for (key in source) {
    FORCED = isForced(GLOBAL ? key : TARGET + (STATIC ? '.' : '#') + key, options.forced);
    // contains in native
    USE_NATIVE = !FORCED && nativeSource && hasOwn(nativeSource, key);

    targetProperty = target[key];

    if (USE_NATIVE) if (options.dontCallGetSet) {
      descriptor = getOwnPropertyDescriptor(nativeSource, key);
      nativeProperty = descriptor && descriptor.value;
    } else nativeProperty = nativeSource[key];

    // export native or implementation
    sourceProperty = (USE_NATIVE && nativeProperty) ? nativeProperty : source[key];

    if (USE_NATIVE && typeof targetProperty == typeof sourceProperty) continue;

    // bind methods to global for calling from export context
    if (options.bind && USE_NATIVE) resultProperty = bind(sourceProperty, global);
    // wrap global constructors for prevent changes in this version
    else if (options.wrap && USE_NATIVE) resultProperty = wrapConstructor(sourceProperty);
    // make static versions for prototype methods
    else if (PROTO && isCallable(sourceProperty)) resultProperty = uncurryThis(sourceProperty);
    // default case
    else resultProperty = sourceProperty;

    // add a flag to not completely full polyfills
    if (options.sham || (sourceProperty && sourceProperty.sham) || (targetProperty && targetProperty.sham)) {
      createNonEnumerableProperty(resultProperty, 'sham', true);
    }

    createNonEnumerableProperty(target, key, resultProperty);

    if (PROTO) {
      VIRTUAL_PROTOTYPE = TARGET + 'Prototype';
      if (!hasOwn(path, VIRTUAL_PROTOTYPE)) {
        createNonEnumerableProperty(path, VIRTUAL_PROTOTYPE, {});
      }
      // export virtual prototype methods
      createNonEnumerableProperty(path[VIRTUAL_PROTOTYPE], key, sourceProperty);
      // export real prototype methods
      if (options.real && targetPrototype && (FORCED || !targetPrototype[key])) {
        createNonEnumerableProperty(targetPrototype, key, sourceProperty);
      }
    }
  }
};