QueryBuilder serialization

I need to serialize QueryBuilder in my app. I am wondering why don't QueryBuilder implement Serializable? I am looking for a way to store/retrieve QueryBuilder Objects.

You can use the toString() method.

@jprante I gonna save QueryBuilder into DB and then retrieve it as QueryBuilder object so that I can call its manipulation methods. if I save the output of toString, Is there any way to pars it and to convert it into a QueryBuilder object?

In addition, it seems you accept the idea that QueryBuilder should be persistencable. So, why don't QueryBuilder implement Serializable?