Android : How to use retrofit library

I have downloaded the retrofit library and samples from https://github.com/square/retrofit.I want to do image and data caching. But I am not getting how to use that in android.Can Somebody give me an example.I have checked the code

RestAdapter restAdapter = new RestAdapter.Builder()
        .setServer("")     
        .build();

ClientInterface service = restAdapter.create(ClientInterface.class);

Callback callback = new Callback() {

@Override

public void success(Object o, Response response) {
    // Read response here
}

@Override
public void failure(RetrofitError retrofitError) {
    // Catch error here
} }; 
service.findBuffet("sudhakar", callback);

But I am not getting anything. Thanks for the help in advance...