code: function manageIfFewItems() {
      const itemsCount = getLength.call( this, this.items );
      if ( itemsCount < 2 ) return true;
      if ( itemsCount === 2 ) {
          this.index = 1 - this.index;
          this.expanded = false;
          return true;
      }
      // More than 2 items to manage.
      return false;
  }
docs: For two items, we never show the whole list, but we just change the selection on click.
  @this ViewXJS
  @returns {boolean} `true` if there are at most 2 items.