docs: function copyContentOf() {
      const
          that = this,
          items = this.items,
          div = Dom.div( "thm-ele8" );
      items.forEach( function ( item, index ) {
          const clonedItem = Dom.div( that.index === index ? "thm-bgSL" : "thm-bg3" );
          if ( typeof item === 'string' ) {
              clonedItem.textContent = item;
          } else {
              clonedItem.innerHTML = Dom( item ).innerHTML;
          }
          Dom.add( div, clonedItem );
          const touchable = new Touchable( clonedItem );
          touchable.tap.add( () => {
              that.expanded = false;
              that.index = index;
          } );
      } );
      return div;
  }