public function getUsers()
 {
     $urs = User_Role::getAllFromDb(['role_id' => $this->role_id], $this->dbConnection);
     $user_ids = Db_Linked::arrayOfAttrValues($urs, 'user_id');
     $users = User::getAllFromDb(['user_id' => $user_ids], $this->dbConnection);
     usort($users, 'User::cmp');
     return $users;
 }
 public function getRoles()
 {
     $user_roles = array();
     $user_roles = User_Role::getAllFromDb(['user_id' => $this->user_id], $this->dbConnection);
     if (count($user_roles) <= 0) {
         return array(Role::getOneFromDb(['name' => 'public'], $this->dbConnection));
     }
     //            $roles = Role::getAllFromDb(['role_id'=>array_map(function($e){return $e->role_id;},$user_roles)],
     $roles = Role::getAllFromDb(['role_id' => Db_Linked::arrayOfAttrValues($user_roles, 'role_id')], $this->dbConnection);
     return $roles;
 }