'Validate and return an ID for a course if given org, course, and url_name.'

@staticmethod
def get_id(org, course, url_name):

    if (not url_name):
        raise ValueError("Can't    load    a    course    without    a    'url_name'    (or    'name')    set.        Set    url_name.")
    return SlashSeparatedCourseKey(org, course, url_name)
