private static boolean isOutOfSources(@NotNull Project project, @NotNull VirtualFile file) {
    return OutOfSourcesChecker.EP_NAME.getExtensionList().stream()
      .anyMatch(checker -> FileTypeRegistry.getInstance().isFileOfType(file, checker.getFileType()) && checker.isOutOfSources(project, file));
  }
private static boolean isOutOfSources(@NotNull Project project, @NotNull VirtualFile file)