code: def sign(self, msg: Dict) -> Dict:
          
          ser = serialize_msg_for_signing(msg, topLevelKeysToIgnore=[f.SIG.nm])
          bsig = self.naclSigner.signature(ser)
          sig = base58.b58encode(bsig).decode("utf-8")
          return sig
docs: Return a signature for the given message.