def find_persons_by_type(self, type, nationality=None, gender=None,
                             firstletter=None, orderby='view-week-count',
                             page=1, count=20):
        """doc: http://open.youku.com/docs/docs?id=89
        """
        url = 'https://openapi.youku.com/v2/persons/by_type.json'
        params = {
            'client_id': self.client_id,
            'type': type,
            'nationality': nationality,
            'gender': gender,
            'firstletter': firstletter,
            'orderby': orderby,
            'page': page,
            'count': count
        }
        params = remove_none_value(params)
        r = requests.get(url, params=params)
        check_error(r)
        return r.json()