| 'use strict'; | 
| var hasOwn = require('./internals/has-own-property'); | 
| var isArray = require('./internals/is-array'); | 
| var isForced = require('./internals/is-forced'); | 
| var shared = require('./internals/shared-store'); | 
|   | 
| var data = isForced.data; | 
| var normalize = isForced.normalize; | 
| var USE_FUNCTION_CONSTRUCTOR = 'USE_FUNCTION_CONSTRUCTOR'; | 
| var ASYNC_ITERATOR_PROTOTYPE = 'AsyncIteratorPrototype'; | 
|   | 
| var setAggressivenessLevel = function (object, constant) { | 
|   if (isArray(object)) for (var i = 0; i < object.length; i++) data[normalize(object[i])] = constant; | 
| }; | 
|   | 
| module.exports = function (options) { | 
|   if (typeof options == 'object') { | 
|     setAggressivenessLevel(options.useNative, isForced.NATIVE); | 
|     setAggressivenessLevel(options.usePolyfill, isForced.POLYFILL); | 
|     setAggressivenessLevel(options.useFeatureDetection, null); | 
|     if (hasOwn(options, USE_FUNCTION_CONSTRUCTOR)) { | 
|       shared[USE_FUNCTION_CONSTRUCTOR] = !!options[USE_FUNCTION_CONSTRUCTOR]; | 
|     } | 
|     if (hasOwn(options, ASYNC_ITERATOR_PROTOTYPE)) { | 
|       shared[ASYNC_ITERATOR_PROTOTYPE] = options[ASYNC_ITERATOR_PROTOTYPE]; | 
|     } | 
|   } | 
| }; |