text:      /**
       *  Repeats source as long as condition holds emulating a while loop.
       * There is an alias for this method called 'whileDo' for browsers <IE9
       *
       * @param {Function} condition The condition which determines if the source will be repeated.
       * @param {Observable} source The observable sequence that will be run if the condition function returns true.
       * @returns {Observable} An observable sequence which is repeated as long as the condition holds.  
       */
      var observableWhileDo = Observable['while'] = Observable.whileDo = function (condition, source) {
          return enumerableWhile(condition, source).concat();
      };
  