code: def receive_accept(self, msg):
          '''
          Returns either an Accepted or Nack message in response. The Acceptor's state must be persisted
          to disk prior to transmitting the Accepted message.
          '''
          if self.promised_id is None or msg.proposal_id >= self.promised_id:
              self.promised_id = msg.proposal_id
              self.accepted_id = msg.proposal_id
              self.accepted_value = msg.proposal_value
              return Accepted(self.network_uid, msg.proposal_id, msg.proposal_value)
          else:
              return Nack(self.network_uid, msg.from_uid, msg.proposal_id, self.promised_idf receive_accept(self, msg):
          '''
          Returns either an Accepted or Nack message in response. The Acceptor's state must be persisted
          to disk prior to transmitting the Accepted message.
          '''
          if self.promised_id is None or msg.proposal_id >= self.promised_id:
              self.promised_id = msg.proposal_id
              self.accepted_id = msg.proposal_id
              self.accepted_value = msg.proposal_value
              return Accepted(self.network_uid, msg.proposal_id, msg.proposal_value)
          else:
              return Nack(self.network_uid, msg.from_uid, msg.proposal_id, self.promised_id)
docs: Returns either an Accepted or Nack message in response. The Acceptor's state must be persisted
          to disk prior to transmitting the Accepted message.