src/Traits/Relationshipable.php
public function setParent(ElasticsearchModel $parent)
    {
        $this->_parent = $parent;
        $this->setParentId($parent->getId());
    }
public function setParent(ElasticsearchModel $parent)
    {
        $this->_parent = $parent;
        $this->setParentId($parent->getId());
    }
Set parent document.

@param ElasticsearchModel $parent