code: function AsyncExecService() {
  
      /**
       * Set a timeout
       */
      this.setTimeout = function (callback, timeout) {
          return setTimeout(callback, timeout);
      };
  
      /**
       * Set an interval
       */
      this.setInterval = function (callback, interval) {
          return setInterval(callback, interval);
      };
  
      /**
       * Clear a timeout
       */
      this.clearTimeout = function (timeoutId) {
          clearTimeout(timeoutId);
      };
  
      /**
       * Clear an interval
       */
      this.clearInterval = function (intervalId) {
          clearInterval(intervalId);
      };
  }
docs: So we can test the set/clear Timeout/Intervals