Empty Constructor Necessary?

[raysuhyunlee]

Hi! First of all thank you for the great library! I love this :+1:

I've noticed that when I try to get an object using getObject(), it crashes if the object class doesn't have an empty constructor. After looking the code for few minutes I could understand why it requires it. Is an empty constructor necessary for getObject to work? If so, it would be great if some explanation was added into the cookbook or somewhere so that other guys don't struggle with same problem :) Meanwhile, I wonder how it is possible to recover the values in the object while using an empty constructor. May I ask how these generally works?