public function hasChild($parent, $child)
    {
        return isset($this->children[$parent->name][$child->name]);
    }
public function hasChild($parent, $child)
    {
        return isset($this->children[$parent->name][$child->name]);
    }
public function hasChild ( $ parent , $ child ) { return isset ( $ this -> children [ $ parent -> name ] [ $ child -> name ] ) ; }
{@inheritdoc}
{