code: public static Timestamp ofTimeMicroseconds(long microseconds) {
      long seconds = microseconds / 1_000_000;
      int nanos = (int) (microseconds % 1_000_000 * 1000);
      if (nanos < 0) {
        seconds--;
        nanos += 1_000_000_000;
      }
      checkArgument(
          Timestamps.isValid(seconds, nanos), "timestamp out of range: %s, %s", seconds, nanos);
      return new Timestamp(seconds, nanos);
    }
docs: Creates an instance representing the value of {@code microseconds}.
  
  @throws IllegalArgumentException if the timestamp is outside the representable range