private static void addItemsForMarkers(List<? extends RelatedItemLineMarkerInfo> markers,
                                         List<? super GotoRelatedItem> result) {
    Set<PsiFile> addedFiles = new HashSet<>();
    for (RelatedItemLineMarkerInfo<?> marker : markers) {
      Collection<? extends GotoRelatedItem> items = marker.createGotoRelatedItems();
      for (GotoRelatedItem item : items) {
        PsiElement element = item.getElement();
        if (element instanceof PsiFile file) {
          if (addedFiles.contains(file)) {
            continue;
          }
        }
        if (element != null) {
          ContainerUtil.addIfNotNull(addedFiles, element.getContainingFile());
        }
        result.add(item);
      }
    }
  }
private static void addItemsForMarkers(List<? extends RelatedItemLineMarkerInfo> markers,
                                         List<? super GotoRelatedItem> result)