def METHOD_NAME(self):
    test_slug = "missing-heading"
    factory = mock.Mock()
    chapter_loader = ChaptersLoader(
        factory,
        chapter_number=1,
        content_path=test_slug,
        base_path=self.base_path,
        structure_filename="{}.yaml".format(test_slug)
    )
    self.assertRaises(
        NoHeadingFoundInMarkdownFileError,
        chapter_loader.load
    )