import { OperatorFunction } from 'rxjs';
import { ChangeSummary } from '../ChangeSummary';
import { IChangeSet } from '../../cache/IChangeSet';
/**
 * Accumulates update statistics
 * @typeparam TSource The type of the source.
 * @typeparam TKey The type of the key.
 * @param source The source.
 */
export declare function collectUpdateStats<TSource, TKey>(): OperatorFunction<IChangeSet<TSource, TKey>, ChangeSummary>;