Reactive-Extensions/RxJS

/// <reference path="./observer-lite.ts" />
module Rx {
    export module internals {
        export interface ScheduledObserver<T> extends Observer<T> {
            ensureActive(): void;
        }
    }
}
 
(function() {
    var observer: Rx.internals.ScheduledObserver<boolean>;
    observer.ensureActive();
});