@Nullable
  public static Charset getPreferredModuleEncoding(Chunk<? extends Module> chunk) {
    CompilerEncodingService service = null;
    for (Module module : chunk.getNodes()) {
      if (service == null) {
        service = getInstance(module.getProject());
      }
      final Charset charset = service.getPreferredModuleEncoding(module);
      if (charset != null) {
        return charset;
      }
    }
    return null;
  }
@Nullable
  public static Charset getPreferredModuleEncoding(Chunk<? extends Module> chunk)