code: def raw(self) -> str:
          
          return """Version: {0}
  Type: Membership
  Currency: {1}
  Issuer: {2}
  Block: {3}
  Membership: {4}
  UserID: {5}
  CertTS: {6}
  """.format(self.version,
             self.currency,
             self.issuer,
             self.membership_ts,
             self.membership_type,
             self.uid,
             self.identity_ts)
docs: Return signed raw format string of the Membership instance
  
          :return: