Newbie to GWT_RPC and Extension

[tholmes66]

I've been trying to do my part and research here all apart the GWT-RPC integration threads so I am more well informed.

I did go to google, and I did check out the SmartGWT-Extensions and was lookin at the great code examples gwtrpcds. The two files:
public interface SimpleGwtRPCDSService extends RemoteService {
and
public interface SimpleGwtRPCDSServiceAsync {
are causing me problems.

The:
public interface SimpleGwtRPCDSServiceAsync {
remove method:

public abstract void remove (SimpleGwtRPCDSRecord record, AsyncCallback<Object> asyncCallback);

is showing an error under <Object>

This may have already been discussed and I am sorry for bringing it up again.
I will do more research on this. The error message I get it is:
"AsyncCallback parameterization is not compatible with the return type of SimpleGwtRPCDSService.remove"

Any help on why I get this message? Feel free to tell me I am just an idiot.

Thanks for the help!
Tom