docs: public static void reportWarning(String message, String sourceName,
                                       int lineno, String lineSource,
                                       int lineOffset)
      {
          Context cx = Context.getContext();
          if (cx.hasFeature(FEATURE_WARNING_AS_ERROR))
              reportError(message, sourceName, lineno, lineSource, lineOffset);
          else
              cx.getErrorReporter().warning(message, sourceName, lineno,
                                            lineSource, lineOffset);
      }