DOC Specify the meaning of scoring=None in sklearn.metrics.check_scoring
@@ -432,6 +432,7 @@ def check_scoring(estimator, scoring=None, *, allow_none=False):
A string (see model evaluation documentation) or
a scorer callable object / function with signature
``scorer(estimator, X, y)``.
+ If None, the provided estimator object's `score` method is used.
allow_none : bool, default=False
If no scoring is specified and the estimator has no score function, we
