YII2.0 点击Modal空白处不关闭弹窗

Modal::begin([
    'id' => $modalId,
    'size' => Modal::SIZE_DEFAULT,
    'header' => '<h4 class="modal-title"></h4>',
    'footer' => '<a href="#" class="btn btn-primary btn-sm" data-dismiss="modal">关闭</a>';
    'options'=>[
        'data-backdrop'=>'static',//点击空白处不关闭弹窗
        'data-keyboard'=>false,
    ],
]);