@utils.requires_login<EOL><INDENT>def cancel_orders(self, market_id, instructions, customer_ref=None):<DEDENT>
return self.make_api_request(<EOL>'<STR_LIT>',<EOL>'<STR_LIT>',<EOL>utils.get_kwargs(locals()),<EOL>model=models.CancelExecutionReport,<EOL>)<EOL>
Cancel all bets OR cancel all bets on a market OR fully or
        partially cancel particular orders on a market.

        :param str market_id: If not supplied all bets are cancelled
        :param list instructions: List of `CancelInstruction` objects
        :param str customer_ref: Optional order identifier string