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Copyright (c) Microsoft Corporation. All rights reserved.
Licensed under the Apache License, Version 2.0 (the "License"); you may not use
this file except in compliance with the License. You may obtain a copy of the
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See the Apache Version 2.0 License for specific language governing permissions
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***************************************************************************** */


/// <reference no-default-lib="true"/>

interface String {
    /**
     * Returns a new String consisting of the single UTF-16 code unit located at the specified index.
     * @param index The zero-based index of the desired code unit. A negative index will count back from the last item.
     */
    at(index: number): string | undefined;
}