I've thought of doing that, but it would only produce meaningful results for LR-like models. When used on, say, an `SVC(probability=True), an SGDClassifier with the modified Huber loss or AdaBoost, the results come out wrong. If the function takes predict_proba output, it can work for any probability model, and it can be used in a self-training EM loop, which is why I wanted this function in the first place.