private static @NotNull Set<File> getFilesContainer(CompileContext context, final Key<Set<File>> dataKey) {
    Set<File> files = dataKey.get(context);
    if (files == null) {
      files = FileCollectionFactory.createCanonicalFileSet();
      dataKey.set(context, files);
    }
    return files;
  }
private static @NotNull Set<File> getFilesContainer(CompileContext context, final Key<Set<File>> dataKey)