def METHOD_NAME(loader):
    """Test that we can load all baked in TSC problems into nested pd.DataFrames."""
    # should work for all
    X, y = loader()
    assert isinstance(X, pd.DataFrame)
    assert isinstance(y, np.ndarray)
    assert y.ndim == 1
    X = loader(return_X_y=False)
    assert isinstance(X, pd.DataFrame)