Drag placeholder for rendered elements

Hello! I'm digging through code and I'm trying to achieve a placeholder effect while dragging the element? Something similar already exists for dragging blocks.

If I want to add something to achieve this, what method would I need to modify/hook into? I don't see a startDrag option for elements on the canvas.

  /**
   * Start block dragging
   * @private
   */
  startDrag: function startDrag(e) {
    //Right or middel click
    if (e.button !== 0) {
      return;
    }

    if (!this.config.getSorter) {
      return;
    }

    this.config.em.refreshCanvas();
    var sorter = this.config.getSorter();
    sorter.setDragHelper(this.el, e);
    sorter.setDropContent(this.model.get('content'));
    sorter.startSort(this.el);
    (0, _mixins.on)(document, 'mouseup', this.endDrag);
  },

similar to: http://gridstackjs.com/