function _handleCollapseBegin( event ) {
      var menu = event.target;
      _handleToggle( menu );
      if ( menu === _rootMenu ) {
        _bodyDom.removeEventListener( 'mousedown', _handleBodyClick );
      }
    }
/**
     * Event handler for when FlyoutMenu collapse transition has begun.
     * Use this to perform post-collapseBegin actions.
     * @param {Event} event - A FlyoutMenu event.
     */
Event handler for when FlyoutMenu collapse transition has begun.
Use this to perform post-collapseBegin actions.
@param {Event} event - A FlyoutMenu event.
Event handler for when FlyoutMenu collapse transition has begun . Use this to perform post - collapseBegin actions . @param { Event } event - A FlyoutMenu event .
function _handleCollapseBegin( event ) {
      var menu = event.target;
      _handleToggle( menu );
      if ( menu === _rootMenu ) {
        _bodyDom.removeEventListener( 'mousedown', _handleBodyClick );
      }
    }
function _handleCollapseBegin ( event ) { var menu = event . target ; _handleToggle ( menu ) ; if ( menu === _rootMenu ) { _bodyDom . removeEventListener ( 'mousedown' , _handleBodyClick ) ; } }
Event handler for when FlyoutMenu collapse transition has begun.
Event handler for when FlyoutMenu collapse transition has begun .