public function testRoots()
 {
     $data = [1, 41];
     $this->assertEquals($data, array_map(function ($value) {
         return $value->id;
     }, Node::find()->roots()->orderBy('id')->all()));
     $this->assertEquals($data, array_map(function ($value) {
         return $value->id;
     }, NodeJoin::find()->roots()->orderBy('id')->all()));
 }
 public function testUpdate()
 {
     $node = Node::findOne(3);
     $node->slug = 'update';
     $this->assertEquals(1, $node->update());
 }