@Override
  public void toData(DataOutput out,
      SerializationContext context) throws IOException {
    out.writeInt(requestId);
    context.getSerializer().writeObject(target, out);
  }
If no response is desired the requestId can be reset by invoking this method
geode-membership/src/main/java/org/apache/geode/distributed/internal/membership/gms/messages/HeartbeatRequestMessage.java