function _handleExpandBegin() {
    this.dispatchEvent( 'expandBegin', { target: this } );

    // Set keyboard focus on first menu item link.
    var activeMenuDom = _activeMenu.getDom().content;
    activeMenuDom.classList.remove( 'u-invisible' );
    // TODO: Remove or uncomment when keyboard navigation is in.
    // var firstMenuLink = activeMenuDom.querySelector( 'a' );
    // firstMenuLink.focus();
  }
/**
   * Event handler for when FlyoutMenu expand transition begins.
   * Use this to perform post-expandBegin actions.
   */
Event handler for when FlyoutMenu expand transition begins.
Use this to perform post-expandBegin actions.
Event handler for when FlyoutMenu expand transition begins . Use this to perform post - expandBegin actions .
function _handleExpandBegin() {
    this.dispatchEvent( 'expandBegin', { target: this } );
    var activeMenuDom = _activeMenu.getDom().content;
    activeMenuDom.classList.remove( 'u-invisible' );
  }
function _handleExpandBegin ( ) { this . dispatchEvent ( 'expandBegin' , { target : this } ) ; var activeMenuDom = _activeMenu . getDom ( ) . content ; activeMenuDom . classList . remove ( 'u-invisible' ) ; }
Event handler for when FlyoutMenu expand transition begins.
Event handler for when FlyoutMenu expand transition begins .
// Set keyboard focus on first menu item link. // TODO: Remove or uncomment when keyboard navigation is in. // var firstMenuLink = activeMenuDom.querySelector( 'a' ); // firstMenuLink.focus();