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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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***************************************************************************** */


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

interface ObjectConstructor {
    /**
     * Groups members of an iterable according to the return value of the passed callback.
     * @param items An iterable.
     * @param keySelector A callback which will be invoked for each item in items.
     */
    groupBy<K extends PropertyKey, T>(
        items: Iterable<T>,
        keySelector: (item: T, index: number) => K,
    ): Partial<Record<K, T[]>>;
}