docs: @SuppressWarnings("javadoc")
      private static List<AbstractWarningsParser> all() {
          Hudson instance = Hudson.getInstance();
          if (instance == null) {
              return Lists.newArrayList();
          }
          List<AbstractWarningsParser> parsers = Lists.newArrayList(instance.getExtensionList(AbstractWarningsParser.class));
          addParsersWithDeprecatedApi(instance, parsers);
  
          return parsers;
      }