def METHOD_NAME():
    X_df = pd.DataFrame(
        X_iris, columns=["sepal length", "sepal width", "petal width", "petal width"]
    )
    knn = KNeighborsClassifier()
    sfs = SFS(
        estimator=knn,
        k_features=3,
        forward=True,
        floating=False,
        fixed_features=("sepal length", "sepal width"),
        verbose=0,
    )
    sfs.fit(X_df, y_iris)
    print(sfs.subsets_)
    for k in sfs.subsets_:
        assert 0 in sfs.subsets_[k]["feature_idx"]
        assert 1 in sfs.subsets_[k]["feature_idx"]