code: def delete(self, reason=''):
          
          db.session.delete(self)
          db.session.flush()
          if not self.chatroom.events:
              db.session.delete(self.chatroom)
              db.session.flush()
              delete_room(self.chatroom, reason)
              return True
          return False
docs: Deletes the event chatroom and if necessary the chatroom, too.
  
          :param reason: reason for the deletion
          :return: True if the associated chatroom was also
                   deleted, otherwise False