--- /dev/null
+var has = require('./internals/has');
+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 (has(options, USE_FUNCTION_CONSTRUCTOR)) shared[USE_FUNCTION_CONSTRUCTOR] = !!options[USE_FUNCTION_CONSTRUCTOR];
+ if (has(options, ASYNC_ITERATOR_PROTOTYPE)) shared[USE_FUNCTION_CONSTRUCTOR] = options[ASYNC_ITERATOR_PROTOTYPE];
+ }
+};