docs: def compute_taxes(self, precision=None):
          '''
          Returns the total amount of taxes for this line with a specific 
          number of decimals
          @param precision: int Number of decimal places
          @return: Decimal
          '''
          base = self.gross - self.total_discounts
          return quantize(sum([t.compute(base, precision) for t in self.__taxes]),
                          precision)