/**
  * Return parent model.
  *
  * @return ElasticsearchModel|null
  */
 public function get()
 {
     $parent = $this->child->getParent();
     if ($parent) {
         return $parent;
     }
     $parentClass = $this->parentClass;
     $parentId = $this->child->getParentId();
     $innerHits = $this->child->getInnerHits();
     if ($innerHits) {
         $attributes = $innerHits->getParent($parentClass::getType());
         $parent = new $parentClass($attributes);
     } elseif ($parentId) {
         $parent = $parentClass::find($parentId);
     }
     if ($parent) {
         $this->child->setParent($parent);
     }
     return $parent;
 }