@Override
  @Nullable
  public StructureViewBuilder getStructureViewBuilder(@NotNull final FileType fileType, @NotNull final VirtualFile file, @NotNull final Project project) {
    if (!(fileType instanceof LanguageFileType)) return null;

    final PsiFile psiFile = PsiManager.getInstance(project).findFile(file);
    if (psiFile == null) return null;

    final PsiStructureViewFactory factory = LanguageStructureViewBuilder.getInstance().forLanguage(psiFile.getLanguage());
    return factory == null ?  null : factory.getStructureViewBuilder(psiFile);
  }
@Override
  @Nullable
  public StructureViewBuilder getStructureViewBuilder(@NotNull final FileType fileType, @NotNull final VirtualFile file, @NotNull final Project project)