@NotNull
  private static PerFileMappingsEx<Charset> createMappings(@NotNull Project project) {
    EncodingProjectManagerImpl prjManager = (EncodingProjectManagerImpl)EncodingProjectManager.getInstance(project);
    return new PerFileMappingsEx<>() {
      @NotNull
      @Override
      public Map<VirtualFile, Charset> getMappings() {
        return new HashMap<>(prjManager.getAllMappings());
      }

      @Override
      public void setMappings(@NotNull Map<VirtualFile, Charset> mappings) {
        prjManager.setMapping(mappings);
      }

      @Override
      public void setMapping(@Nullable VirtualFile file, Charset value) {
        throw new UnsupportedOperationException();
      }

      @Override
      public Charset getMapping(@Nullable VirtualFile file) {
        throw new UnsupportedOperationException();
      }

      @Nullable
      @Override
      public Charset getDefaultMapping(@Nullable VirtualFile file) {
        return prjManager.getEncoding(file, true);
      }
    };
  }
@NotNull
  private static PerFileMappingsEx<Charset> createMappings(@NotNull Project project)