/**
  * @param $name
  * @param null $parentId
  * @return PowerGroup
  * @throws \Exception
  */
 public function createNewPowerGroup($name, $parentId = null)
 {
     if ($name == null || sizeof($name) < 1) {
         throw new \Exception("Invalid power group name - null or zero-length");
     }
     $group = new PowerGroup();
     $group->name = $name;
     if ($parentId != null) {
         $group->group = $parentId;
     }
     $group->save();
     return $group;
 }