code: public static boolean sleep(long millis) {
  		boolean interrupted = false;
  
  		try {
  			Thread.sleep(millis);
  		} catch (InterruptedException e) {
  			Exceptions.ignore(e);
  			Thread.currentThread().interrupt();
  			interrupted = true;
  		}
  		return !interrupted;
  	}
docs: Causes the current {@linkplain Thread} to sleep.
  <p>
  In addition to {@linkplain Thread#sleep(long)} this function automatically handles possible
  {@linkplain InterruptedException}s by handling and discarding the exception.
  
  @param millis the sleep timeout.
  @return {@code true} if the sleep operation was not interrupted.
  @see Thread#sleep(long)