'For each Result in ``results``, if ``should_clean`` is True, remove cert_name_long
and cert_name_short from the course and save in the backing modulestore.'

def _commit(self, results):

    for result in results:
        if (not result.should_clean):
            continue
        course = modulestore().get_course(result.course_key)
        del course.cert_name_short
        del course.cert_name_long
        modulestore().update_item(course, ModuleStoreEnum.UserID.mgmt_command)
