def get_followers(self, userid = None, username=None, page=1, query_id=None):
'''
Obtiene la lista de followers de un usuario
:param userid: id del usuario (user.id)
:type userid: :class:`string`
:param username: nombre del usuario (user.username)
:type username: :class:`string`
:param page: numero de pagina a mostrar
:type param: int
:param query_id: identificador de busqueda
:type query_id: int
:returns: lista de tuplas de la forma [query_id, [(id, username, avatar)]]
'''
if username is not None:
userkey = self.get_by_username(username, keys_only=True)
elif userid is not None:
userkey = db.Key.from_path(User.kind(), userid)
followers = UserFollowingIndex.gql('WHERE following = :1', userkey)
p = PagedQuery(followers, id = query_id)
##users = [(u.id, u.username, u.profile.avatar) for u in (index.parent() for index in p.fetch_page(page))]
return [p.id, [(u.id, u.username, u.profile.avatar) for u in (index.parent() for index in p.fetch_page(page))]]
