code: function AnonymousObserver(onNext, onError, onCompleted) {
        __super__.call(this);
        this._onNext = onNext;
        this._onError = onError;
        this._onCompleted = onCompleted;
      }
docs: Creates an observer from the specified OnNext, OnError, and OnCompleted actions.
  @param {Any} onNext Observer's OnNext action implementation.
  @param {Any} onError Observer's OnError action implementation.
  @param {Any} onCompleted Observer's OnCompleted action implementation.