def METHOD_NAME():
    drop_null_transformer = DropNullColumns()
    X = pd.DataFrame(
        {"lots_of_null": [None, None, None, None, 5], "no_null": [1, 2, 3, 4, 5]},
    )
    X_expected = X.astype({"lots_of_null": "Int64", "no_null": "int64"})
    drop_null_transformer.fit(X)
    X_t = drop_null_transformer.transform(X)
    assert_frame_equal(X_expected, X_t)