Openimaj and LiblinearAnnotator "train()" method arguments

Question

I am following this tutorial here and have a question regarding this:

LiblinearAnnotator<Record<FImage>, String> ann = new LiblinearAnnotator<Record<FImage>, String>(
                    extractor, Mode.MULTICLASS, SolverType.L2R_L2LOSS_SVC, 1.0, 0.00001);
ann.train(splits.getTrainingDataset());

Now the train() method as per documentation it can take a GroupedDataset as argument. I am passing a VFSGroupDataset with multiple classes and it is failing although the VFSGroupDataset extends GroupedDataset.

Maybe I am a bit confused, but why is it failing?

ANSWER: Use 1.4-SNAPSHOT Version