def getPassword(self):
        """
        Get the password to use for authentication.

        @return: A L{Deferred} which fires with the password, or L{None} if the
            password was not specified.
        """
        if self.password is None:
            return
        return succeed(self.password)

        Get the password to use for authentication.

        @return: A L{Deferred} which fires with the password, or L{None} if the
            password was not specified.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/conch/endpoints.py