code: public static ThreadFactory daemonThreadsNamed(String nameFormat)
      {
          return new ThreadFactoryBuilder()
                  .setNameFormat(nameFormat)
                  .setDaemon(true)
                  .setThreadFactory(new ContextClassLoaderThreadFactory(Thread.currentThread().getContextClassLoader(), defaultThreadFactory()))
                  .build();
      }
docs: Creates a {@link ThreadFactory} that creates named daemon threads.
  using the specified naming format.
  
  @param nameFormat see {@link #threadsNamed(String)}
  @return the created ThreadFactory