code: function _clickHandler(e) {
        if (_settings('mouseEnabled')) {
          var event = sigma.utils.mouseCoords(e);
          event.isDragging =
            (((new Date()).getTime() - _downStartTime) > 100) && _hasDragged;
          _self.dispatchEvent('click', event);
        }
  
        if (e.preventDefault)
          e.preventDefault();
        else
          e.returnValue = false;
  
        e.stopPropagation();
        return false;
      }
docs: The handler listening to the 'click' mouse event. It will redispatch the
  click event, but with normalized X and Y coordinates.
  
  @param {event} e A mouse event.