Method destroy

src/Swappable/Swappable.js:82–88

* Destroys Swappable instance.

()

   * Destroys Swappable instance.
   */
  destroy() {
    super.destroy();

    this.off('drag:start', this._onDragStart)
      .off('drag:over', this._onDragOver)
      .off('drag:stop', this._onDragStop);
  }

  /**
   * Drag start handler