in optional-kubernetes-engine/bookshelf/model_mongodb.py [0:0]
def list_by_user(user_id, limit=10, cursor=None):
cursor = int(cursor) if cursor else 0
results = mongo.db.books\
.find({'createdById': user_id}, skip=cursor, limit=10)\
.sort('title')
books = builtin_list(map(from_mongo, results))
next_page = cursor + limit if len(books) == limit else None
return (books, next_page)