def client_max_amount_forward_swap(self) -> Optional[int]:
        """ returns None if we cannot swap """
        max_swap_amt_ln = self.get_provider_max_reverse_amount()
        if max_swap_amt_ln is None:
            return None
        max_recv_amt_ln = int(self.lnworker.num_sats_can_receive())
        max_amt_ln = int(min(max_swap_amt_ln, max_recv_amt_ln))
        max_amt_oc = self.get_send_amount(max_amt_ln, is_reverse=False) or 0
        min_amt_oc = self.get_send_amount(self.get_min_amount(), is_reverse=False) or 0
        return max_amt_oc if max_amt_oc >= min_amt_oc else None
 returns None if we cannot swap 
electrum/submarine_swaps.py