code: function(evt) {
          this.mouseDown = true;
          this.lastDown = evt.xy;
          if(!this.touch) { // no point displayed until up on touch devices
              this.modifyFeature(evt.xy);
          }
          this.stoppedDown = this.stopDown;
          return !this.stopDown;
      }
docs: Method: down
  Handle mousedown and touchstart.  Adjust the geometry and redraw.
  Return determines whether to propagate the event on the map.
  
  Parameters:
  evt - {Event} The browser event
  
  Returns:
  {Boolean} Allow event propagation