anchor.diff:      Rate = props:get_value(<<"rate">>, FeeLine),
       Cost = props:get_value(<<"cost">>, FeeLine),
       VatLineTotal = price_round(Cost * VatRate / (100 + VatRate)),
  -    NetCost = price_round(Cost - VatLineTotal),
  -    NetRate = price_round(Rate / (100 + VatRate) * 100),
  -    NewValues = [{<<"rate_netto">>, NetRate}
  -                ,{<<"cost_netto">>, NetCost}
  -                ,{<<"rate_brutto">>, Rate}
  -                ,{<<"cost_brutto">>, Cost}
  +    NetCost = Cost - VatLineTotal,
  +    NetRate = Rate / (100 + VatRate) * 100,
  +    NewValues = [{<<"rate_netto">>, price_round(NetRate)}
  +                ,{<<"cost_netto">>, price_round(NetCost)}
  +                ,{<<"rate_brutto">>, price_round(Rate)}
  +                ,{<<"cost_brutto">>, price_round(Cost)}
                   ,{<<"vat_line_total">>, VatLineTotal}
                   ],
       props:set_values(NewValues, FeeLine).
  
positive.code: enhance_no_or_zero_vat(FeeLine, _OnbillCfg) ->
      Rate = props:get_value(<<"rate">>, FeeLine),
      Cost = props:get_value(<<"cost">>, FeeLine),
      NewValues = [{<<"rate_netto">>, Rate}
                  ,{<<"cost_netto">>, Cost}
                  ,{<<"rate_brutto">>, Rate}
                  ,{<<"cost_brutto">>, Cost}
                  ,{<<"vat_line_total">>, 0.0}
                  ],
      props:set_values(NewValues, FeeLine).
  
negative.code:     Rate = props:get_value(<<"rate">>, FeeLine),
      Cost = props:get_value(<<"cost">>, FeeLine),
      VatLineTotal = price_round(Cost * VatRate / 100),
      BruttoCost = Cost + VatLineTotal,
      BruttoRate = Rate * (100 + VatRate) / 100,
      NewValues = [{<<"rate_netto">>, price_round(Rate)}
                  ,{<<"cost_netto">>, price_round(Cost)}
                  ,{<<"rate_brutto">>, price_round(BruttoRate)}
                  ,{<<"cost_brutto">>, price_round(BruttoCost)}
                  ,{<<"vat_line_total">>, VatLineTotal}
                  ],
      props:set_values(NewValues, FeeLine).
  