code: function toggleLayout() {
      $('.nodeLabel').remove();
      isPaused = !isPaused;
      if (isPaused) {
          $('#toggleLayout').html('<i class="fa fa-play"></i>Resume layout');
          renderer.pause();
      } else {
          $('#toggleLayout').html('<i class="fa fa-pause"></i>Pause layout');
          renderer.resume();
      }
      return false;
  }
docs: Allows the rendering to be paused or resumed
  @returns {boolean}