code: public static Timestamp parseTimestamp(String timestamp) {
      TemporalAccessor temporalAccessor = timestampParser.parse(timestamp);
      Instant instant = Instant.from(temporalAccessor);
      return ofTimeSecondsAndNanos(instant.getEpochSecond(), instant.getNano());
    }
docs: Creates a Timestamp instance from the given string. String is in the RFC 3339 format without
  the timezone offset (always ends in "Z").