'returns the course_id of the course if it was found, else None
Note: we return the course_id instead of a boolean here since the found course may have
a different id than the given course_id when ignore_case is True.
Args:
* course_id (CourseKey)
* ignore_case (bool): If True, do a case insensitive search. If
False, do a case sensitive search'

@strip_key
def has_course(self, course_id, ignore_case=False, **kwargs):

    assert isinstance(course_id, CourseKey)
    store = self._get_modulestore_for_courselike(course_id)
    return store.has_course(course_id, ignore_case, **kwargs)
