'Determine which message to show the user.
The message can be configured per-course and depends
on how the user is trying to access the course
(trying to enroll or accessing courseware).
Arguments:
access_point (str): Either "courseware" or "enrollment"
Returns:
str: The message key.  If the access point is not valid,
returns None instead.'

def message_key_for_access_point(self, access_point):

    if (access_point == 'enrollment'):
        return self.enroll_msg_key
    elif (access_point == 'courseware'):
        return self.access_msg_key
