/**
  * Get or create root category.
  * @return null|Category
  */
 protected function getRoot()
 {
     if (!$this->rootCategory) {
         $this->rootCategory = $this->createCategory(['name' => '0_ROOT', 'enabled' => 1]);
         $this->rootCategory->refresh();
         $this->rootCategory->parent = 0;
         $this->rootCategory->save();
     }
     return $this->rootCategory;
 }