code: public static ThreadFactory threadsNamed(String nameFormat)
      {
          return new ThreadFactoryBuilder()
                  .setNameFormat(nameFormat)
                  .setThreadFactory(new ContextClassLoaderThreadFactory(Thread.currentThread().getContextClassLoader(), defaultThreadFactory()))
                  .build();
      }
docs: Creates a {@link ThreadFactory} that creates named threads
  using the specified naming format.
  
  @param nameFormat a {@link String#format(String, Object...)}-compatible
  format string, to which a string will be supplied as the single
  parameter. This string will be unique to this instance of the
  ThreadFactory and will be assigned sequentially.
  @return the created ThreadFactory