code: public final DeepLearningModel initModel() {
      try {
        lock_data();
        checkParams();
        final DataInfo dinfo = prepareDataInfo();
        final Vec resp = dinfo._adaptedFrame.lastVec(); //convention from DataInfo: response is the last Vec
        float[] priorDist = classification ? new MRUtils.ClassDist(resp).doAll(resp).rel_dist() : null;
        final DeepLearningModel model = new DeepLearningModel(dest(), self(), source._key, dinfo, (DeepLearning)this.clone(), priorDist);
        model.model_info().initializeMembers();
        return model;
      }
      finally {
        unlock_data();
      }
    }
docs: Create an initial Deep Learning model, typically to be trained by trainModel(model)
  @return Randomly initialized model