Stacking - training a machine learning model using the predictions of other models as features.
https://en.wikipedia.org/wiki/Ensemble_learning#Stacking
In breast_cancer_example.py, we use decision trees, logistic regressions, and k-nearest neighbors models for the features and a random forest for the top-level model on the UCI ML Breast Cancer Wisconsin (Diagnostic) dataset, via sklearn.
https://scikit-learn.org/stable/modules/generated/sklearn.datasets.load_breast_cancer.html