def METHOD_NAME(self):
    """Test that mlb_transform adds new transformed columns"""
    # Arrange
    test_df = pd.DataFrame(
        {
            "id": [1, 2],
            "mapping_types": [
                ["building", "waterway"],
                ["building", "road"],
            ],
        }
    )
    # Act
    transformed_df = self.service.mlb_transform(
        test_df, "mapping_types", "mapping_types_"
    )
    # Assert
    self.assertEqual(transformed_df.shape, (2, 4))
    self.assertEqual(transformed_df["mapping_types_building"].tolist(), [1, 1])
    self.assertEqual(transformed_df["mapping_types_waterway"].tolist(), [1, 0])
    self.assertEqual(transformed_df["mapping_types_road"].tolist(), [0, 1])
    self.assertEqual(transformed_df["id"].tolist(), [1, 2])