code: public static Version valueOf(final String value) {
          if (value != null) {
              final Instant time = parse(value);
              if (time != null) {
                  return new Version(time);
              }
          }
          return null;
      }
docs: Create a Version object from a string value.
  
  @param value the header value
  @return a Version header or null if the value is not parseable