Pinsave/counterstrike

1/*! *****************************************************************************2Copyright (c) Microsoft Corporation. All rights reserved.3Licensed under the Apache License, Version 2.0 (the "License"); you may not use4this file except in compliance with the License. You may obtain a copy of the5License at http://www.apache.org/licenses/LICENSE-2.06 7THIS CODE IS PROVIDED ON AN *AS IS* BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY8KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED9WARRANTIES OR CONDITIONS OF TITLE, FITNESS FOR A PARTICULAR PURPOSE,10MERCHANTABLITY OR NON-INFRINGEMENT.11 12See the Apache Version 2.0 License for specific language governing permissions13and limitations under the License.14***************************************************************************** */15 16 17/// <reference no-default-lib="true"/>18 19interface String {20    /**21     * Returns a new String consisting of the single UTF-16 code unit located at the specified index.22     * @param index The zero-based index of the desired code unit. A negative index will count back from the last item.23     */24    at(index: number): string | undefined;25}26