@Override
      public Set<PsiFile> search(@Nullable Module module, @NotNull Project project) {
        List<IndexedRelevantResource<String, XsdNamespaceBuilder>> resources = XmlNamespaceIndex.getAllResources(module, project);

        HashSet<PsiFile> files = new HashSet<>();
        PsiManager psiManager = PsiManager.getInstance(project);
        for (IndexedRelevantResource<String, XsdNamespaceBuilder> resource : resources) {
          VirtualFile file = resource.getFile();
          PsiFile psiFile = psiManager.findFile(file);
          ContainerUtil.addIfNotNull(files, psiFile);
        }
        return files;
      }
@Override
      public Set<PsiFile> search(@Nullable Module module, @NotNull Project project)