///
module Rx {
export interface Observable {
/**
* Converts the observable sequence to a Map if it exists.
* @param {Function} keySelector A function which produces the key for the Map.
* @param {Function} [elementSelector] An optional function which produces the element for the Map. If not present, defaults to the value from the observable sequence.
* @returns {Observable} An observable sequence with a single value of a Map containing the values from the observable sequence.
*/
toMap(keySelector: (value: T) => TKey): Observable