def version(self):
if self._server_version is None:<EOL><INDENT>try:<EOL><INDENT>data = self.http_get('<STR_LIT>')<EOL>self._server_version = data['<STR_LIT:version>']<EOL>self._server_revision = data['<STR_LIT>']<EOL><DEDENT>except Exception:<EOL><INDENT>self._server_version = self._server_revision = '<STR_LIT>'<EOL><DEDENT><DEDENT>return self._server_version, self._server_revision<EOL>
Returns the version and revision of the gitlab server.

        Note that self.version and self.revision will be set on the gitlab
        object.

        Returns:
            tuple (str, str): The server version and server revision.
                              ('unknown', 'unknwown') if the server doesn't
                              perform as expected.