'#attributes' =>
[ 'id' => 'menu-overview',
],
'#tabledrag' =>
[ [ 'action' => 'match',
'relationship' => 'parent',
'group' => 'menu-parent',
'subgroup' => 'menu-parent',
'source' => 'menu-id',
'hidden' => TRUE,
'limit' =>
$this->menuTree->
maxDepth() - 1,
],
[ 'action' => 'order',
'relationship' => 'sibling',
'group' => 'menu-weight',
],
],
];
$form['links'
]['#empty'
] =
$this->
t('There are no menu links yet. <a href=":url">Add link</a>.',
[ ':url' => Url::
fromRoute('entity.menu.add_link_form',
['menu' =>
$this->entity->
id()],
[