constructor(draggable) {
    super(draggable);

    /**
     * Focusable options
     * @property {Object} options
     * @type {Object}
     */
    this.options = {
      ...defaultOptions,
      ...this.getOptions(),
    };

    this[onInitialize] = this[onInitialize].bind(this);
    this[onDestroy] = this[onDestroy].bind(this);
  }
Focusable constructor.
@constructs Focusable
@param {Draggable} draggable - Draggable instance