import { IndexedSelector } from '../IndexedSelector';
import GroupedIterable from '../GroupedIterable';
import { EqualityComparer } from '../blinq';
declare module '../Enumerable' {
    interface Enumerable<T> {
        groupBy<TKey>(this: Enumerable<T>, keySelector: IndexedSelector<T, TKey>, equalityComparer?: EqualityComparer<TKey>): Enumerable<GroupedIterable<TKey, T>>;
    }
}