code: function() {
          if(!this._isStopped) {
              return;
          }
  
          this._isStopped = false;
          var processedBuffer = this._processedBuffer;
          if(processedBuffer.length) {
              this._processedBuffer = [];
              nextTick(function() {
                  while(processedBuffer.length) {
                      processedBuffer.shift()();
                  }
              });
          }
  
          this._hasPendingTasks() && this._scheduleRun();
      }
docs: Starts processing of queue