code: public function revoke($role, $userId)
      {
          if ($this->isEmptyUserId($userId)) {
              return false;
          }
  
          unset($this->_checkAccessAssignments[(string) $userId]);
          return $this->db->createCommand()
              ->delete($this->assignmentTable, ['user_id' => (string) $userId, 'item_name' => $role->name])
              ->execute() > 0;
      }
docs: {@inheritdoc}