code: public static long toEndTime(Clock clock, Object timeout)
    {
      Timespan t = toTimespan(timeout);
      if(t == null)
        return 0;
      if(clock == null)
        clock = SystemClock.INSTANCE;
  
      if(t.getDurationInMilliseconds() == 0)
        return 0;
  
      return t.futureTimeMillis(clock);
    }
docs: Computes the end time = now + timeout
  
  @param clock can be <code>null</code> to use system clock
  @param timeout (see {@link #toTimespan(Object)})
  @return 0 if