couchDB update issue

let connectionProperties = ConnectionProperties(host: "localhost", port: 5984, secured: false)
let client = CouchDBClient(connectionProperties: connectionProperties)
let database = client.database("test")

func test() {
    let dict = ["key":"value"]
    let json = JSON(dict)
    database.create(json) { id, revision, doc, error in
        if let id = id {
            database.retrieve(id) { doc, error in
                if let doc = doc {
                    let id = doc["_id"].stringValue
                    let rev = doc["_rev"].stringValue
                    var newDocument = doc
                    newDocument["key"] = "updated value"
                    
                    database.update(id, rev: rev, document: newDocument) { rev, doc, error in
                        print("update callback")
                        if let rev = rev {
                            print(rev)
                        } else {
                            print(error!)
                        }
                    }
                }
            }
        }
    }
}

test()

// update callback is never called after the database.update call...