code: def sign(self, authenticator):
  		
  		self.authid = authenticator.authid
  		self.signature = b"\0" * authenticator.authlen  # provide authlen
  		self.signature = authenticator.sign(self.as_string(forsigning=True))
  		assert len(self.signature) == authenticator.authlen
docs: Sign this OMAPI message.
  		@type authenticator: OmapiAuthenticatorBase