code: public static String createInbox() {
  		byte[] bytes = new byte[16];
  		ThreadLocalRandom.current().nextBytes(bytes);
  		return "_INBOX." + new BigInteger(bytes).abs().toString(16);
  	}
docs: Generates a random string used for creating a unique string. The {@code request} methods rely on this
  functionality.
  
  @return a unique random string.