'Set the user tag for the current course and the current user for a given key
scope: the current scope of the runtime
key: the key that to the value to be set
value: the value to set'

def set_tag(self, scope, key, value):

    if (scope != user_course_tag_api.COURSE_SCOPE):
        raise ValueError('unexpected    scope    {0}'.format(scope))
    return user_course_tag_api.set_course_tag(self._get_current_user(), self.runtime.course_id, key, value)
