src/Models/Tree.php
public function getParent($columns = ['*'])
	{
		$columns = $this->formatColumns($columns);
		return $this->getNode($this->getParentKey(), $columns);
	}
public function getParent($columns = ['*'])
	{
		$columns = $this->formatColumns($columns);
		return $this->getNode($this->getParentKey(), $columns);
	}
获取父级的Node

@return mixed      得到父级元素