def METHOD_NAME(self):
    for mode in self.filtered(lambda x: x.bank_account_link == "fixed"):
        if not mode.fixed_journal_id:
            raise ValidationError(
                _(
                    "On the payment mode '%s', the bank account link is "
                    "'Fixed' but the fixed bank journal is not set"
                )
                % mode.name
            )
        else:
            if mode.payment_method_id.payment_type == "outbound":
                if (
                    mode.payment_method_id.id
                    not in mode.fixed_journal_id.outbound_payment_method_ids.ids
                ):
                    raise ValidationError(
                        _(
                            "On the payment mode '%s', the payment method "
                            "is '%s', but this payment method is not part "
                            "of the payment methods of the fixed bank "
                            "journal '%s'"
                        )
                        % (
                            mode.name,
                            mode.payment_method_id.name,
                            mode.fixed_journal_id.name,
                        )
                    )
            else:
                if (
                    mode.payment_method_id.id
                    not in mode.fixed_journal_id.inbound_payment_method_ids.ids
                ):
                    raise ValidationError(
                        _(
                            "On the payment mode '%s', the payment method "
                            "is '%s' (it is in fact a debit method), "
                            "but this debit method is not part "
                            "of the debit methods of the fixed bank "
                            "journal '%s'"
                        )
                        % (
                            mode.name,
                            mode.payment_method_id.name,
                            mode.fixed_journal_id.name,
                        )
                    )