function WithLatestFromObservable(source, sources, resultSelector) {
      this._s = source;
      this._ss = sources;
      this._cb = resultSelector;
      __super__.call(this);
    }
Returns the values from the source observable sequence until the other observable sequence produces a value.
@param {Observable | Promise} other Observable sequence or Promise that terminates propagation of elements of the source sequence.
@returns {Observable} An observable sequence containing the elements of the source sequence up to the point the other sequence interrupted further propagation.