private static void process(@Nullable ModPsiUpdater updater, PsiMethod method) {
      final PsiParameterList parameterList = method.getParameterList();
      final PsiParameter[] parameters = parameterList.getParameters();
      if (parameters.length == 0) {
        return;
      }
      final PsiParameter lastParameter = parameters[parameters.length - 1];
      if (!lastParameter.isVarArgs()) {
        return;
      }
      final PsiTypeElement typeElement = lastParameter.getTypeElement();
      if (typeElement == null) {
        return;
      }
      final List<PsiElement> refElements = updater == null ? getReferences(method) : 
                                           ContainerUtil.map(getReferences(method), e -> updater.getWritable(e));
      performModification(method, parameters, lastParameter, typeElement, refElements);
    }
private static void process(@Nullable ModPsiUpdater updater, PsiMethod method)