@fluent<EOL><INDENT>def chain(self, operation=ChainOperator.AND):<DEDENT>
if isinstance(operation, str):<EOL><INDENT>operation = ChainOperator(operation)<EOL><DEDENT>self._chain = operation<EOL>return self<EOL>
Start a chain operation

        :param ChainOperator, str operation: how to combine with a new one
        :rtype: Query