code: public static String prepareForNumericParsing(final String inputStr) {
          if (inputStr == null) {
              return EMPTY;
          }
          final Matcher matcher = PATTERN_FOR_NUM_PARSING_PREP.matcher(inputStr);
          return matcher.replaceAll("");
      }
docs: Remove " and spaces from the input string.
  @param inputStr
  @return if null, return empty