code: public static final SingleNumericalValue parseSingleNumericValue (final String value) {
          // decimal constant
          final Matcher decimalMatcher = DECIMAL_CONSTANT_PATTERN.matcher(value);
          if (decimalMatcher.matches()) return new SingleNumericalValue(parseDecimalConstantString(value));
          // hex constant
          final Matcher hexMatcher = HEX_CONSTANT_PATTERN.matcher(value);
          if (hexMatcher.matches()) return new SingleNumericalValue(parseHexConstantString(value));
          // base 64 constant
          final Matcher base64Matcher = BASE_64_CONSTANT_PATTERN.matcher(value);
          if (base64Matcher.matches()) return new SingleNumericalValue(parseBase64ConstantString(value));
          // none of the above
          return null;
      }
docs: Parses a {@link SingleNumericalValue} from a {@link String}. The parameter must contain an integer value in
  decimal, hexadecimal, or Base64 format. If it does not, <code>null</code> will be returned.
  
  @param value the {@link String} to parse
  @return a {@link SingleNumericalValue} with the parsed value or <code>null</code>