code: public static MeterValue valueOf(String value) {
          if (isNumber(value)) {
              return new MeterValue(Long.parseLong(value));
          }
          return new MeterValue(durationConverter.convert(value));
      }
docs: Return a new {@link MeterValue} instance for the given String value. The value may
  contain a simple number, or a {@link Duration duration string}.
  @param value the source value
  @return a {@link MeterValue} instance