code: func (m *GossipMessage) NoopSign() (*SignedGossipMessage, error) {
  	signer := func(msg []byte) ([]byte, error) {
  		return nil, nil
  	}
  	sMsg := &SignedGossipMessage{
  		GossipMessage: m,
  	}
  	_, err := sMsg.Sign(signer)
  	return sMsg, err
  }
docs: // NoopSign creates a SignedGossipMessage with a nil signature