Our team works with pickles from several sklearn versions, so we'd like a way to programmatically determine which version a pickle was saved from.

This information is already saved in the pickle file under the attribute _sklearn_version. However, immediately after unpickling, _sklearn_version gets overwritten with the current scikit-learn library's version.

It would be great if BaseEstimator. __setstate__() stores the original _sklearn_version in another attribute like _sklearn_pickle_version.

(Right now, we have to parse the warning message "Trying to unpickle estimator DecisionTreeClassifier from version 1.0 when using version 0.24.2." to get the original version number.)