checkState((randomId && (id == null)) || (!randomId && (id != null)), "either random ID nor custom ID must be set");
checkState(senderId != null, "sender must not be null");
checkState((currentTime && (time == 0)) || (!currentTime && (time >= 0)), "either current time or custom time must be set");
checkState((randomId && (id == null)) || (!randomId && (id != null)), "either random ID nor custom ID must be set");
checkState(senderId != null, "sender must not be null");
checkState((currentTime && (time == 0)) || (!currentTime && (time >= 0)), "either current time or custom time must be set");