I still think that we should not mutate `n_estimators` here. `n_estimators` is a constructor parameters and should never be mutated inside the `fit` call. If we need to store the actual number of estimators we should do so in a  new `self.n_estimators_` attribute or just the user know that the actual number of estimators the docstring of the `estimators_` attribute might be lower than the requested `n_estimators` constructor parameter and advise to use `len(model.estimators_)` when the true number of estimators is needed.