code: public static ZoneOffset toZoneOffset(final TimeZone self, Instant instant) {
          return self.toZoneId().getRules().getOffset(instant);
      }
docs: Converts this TimeZone to a corresponding {@link java.time.ZoneOffset}. The offset is determined
  using the date/time of specified Instant.
  
  @param self a TimeZone
  @return a ZoneOffset
  @since 2.5.0