Giuliano Wurster

```python class save_best_model(xgb.callback.TrainingCallback): def __init__(self, cvbooster): #super().__init__ self._cvbooster = cvbooster def after_training(self, model): self._cvbooster[:] = [cvpack.bst for cvpack in model.cvfolds] return model ``` ```python cvboosters = [] cv_results = xgb.cv(dtrain=data_dmatrix,...