private void AddUnitInformationInDictionary(Parser.ParserResult result, ProcessingResult conversionResult) { // Add token information. var intergalacticUnit = result.Tokens.First(); var romanEquivalentSymbol = result.Tokens.Last().First(); // get the first character. var validRomanSymbols = RomanNumeralConverter.GetValidSymbols(); if (!validRomanSymbols.Contains(romanEquivalentSymbol)) { conversionResult.ResultType = Parser.ResultType.Unknown; return; } if (!UnitsMapping.ContainsKey(intergalacticUnit)) { UnitsMapping.Add(intergalacticUnit, romanEquivalentSymbol); // Add units mapping. } else { UnitsMapping[intergalacticUnit] = romanEquivalentSymbol; } }