code: protected Map<String, String> getExtra(Dsn dsn) {
          return Util.parseExtra(Lookup.lookup(EXTRA_OPTION, dsn));
      }
docs: Extra data to send with {@link io.sentry.event.Event}s.
  
  @param dsn Sentry server DSN which may contain options.
  @return Extra data to send with {@link io.sentry.event.Event}s.