def METHOD_NAME(self):  # lint-amnesty, pylint: disable=missing-function-docstring
    # get course block from structure only; subtree_edited_on field on modulestore's course block isn't optimized.
    structure = self.effective_structure
    if structure:
        course_block = structure[self.location]
        return getattr(course_block, 'subtree_edited_on', None)