No, db.get() returns an anonymous function that takes a callback. The advantage to this type of api vs the one you mentioned, is db.get() can get more or fewer

No, db.get() returns an anonymous function that takes a callback. The advantage to this type of api vs the one you mentioned, is db.get() can get more or fewer arguments, and callback is always last. db.get() is a bad example, I'm not sure why you'd want to pass anything other than bucket/key to get an object. In this exact case, I imagine it's just for consistency with the rest of the API.