import { SchedulerLike } from 'rxjs';
import { NotifyPropertyChangedType } from '../../notify/notifyPropertyChangedSymbol';
import { Group } from '../IGroupChangeSet';
import { ChangeSetOperatorFunction } from '../ChangeSetOperatorFunction';
/**
 * Groups the source using the property specified by the property selector. Groups are re-applied when the property value changed.
 * When there are likely to be a large number of group property changes specify a throttle to improve performance
 * @typeparam TObject The type of the object.
 * @typeparam TKey The type of the key.
 * @typeparam TGroupKey The type of the group key.
 * @param key The key to watch
 * @param propertyChangedThrottle
 * @param scheduler The scheduler.
 */
export declare function groupOnProperty<TObject, TKey, TGroupKey, TProperty extends keyof TObject>(key: TProperty, propertyChangedThrottle?: number, scheduler?: SchedulerLike): ChangeSetOperatorFunction<TObject, TKey, Group<NotifyPropertyChangedType<TObject>, TKey, TObject[TProperty]>, TObject[TProperty]>;