code: protected Set<String> getMdcTags(Dsn dsn) {
          String val = Lookup.lookup(MDCTAGS_OPTION, dsn);
          if (Util.isNullOrEmpty(val)) {
              val = Lookup.lookup(EXTRATAGS_OPTION, dsn);
              if (!Util.isNullOrEmpty(val)) {
                  logger.warn("The '" + EXTRATAGS_OPTION + "' option is deprecated, please use"
                      + " the '" + MDCTAGS_OPTION + "' option instead.");
              }
          }
  
          return Util.parseMdcTags(val);
      }
docs: Tags to extract from the MDC system and set on {@link io.sentry.event.Event}s, where applicable.
  
  @param dsn Sentry server DSN which may contain options.
  @return Tags to extract from the MDC system and set on {@link io.sentry.event.Event}s, where applicable.