/// module Rx { export interface Observable { /** * Retrieves the value of a specified nested property from all elements in * the Observable sequence. * @param {Arguments} arguments The nested properties to pluck. * @returns {Observable} Returns a new Observable sequence of property values. */ pluck(prop: string): Observable; } } (function() { var o: Rx.Observable<{}>; var n: Rx.Observable; n = o.pluck('abc'); });