从JFrame到Netbeans的JPanel。

I'm rethinking the design of my GUI. I designed a few JFrame with Netbeans automated GUI (yes, I'm lazy, and this generated code is often awful, I know !), but now I want them to be JPanel (actually, to inherit from another class that inherits JPanel). But I had the "setDefaultCloseOperation" modified, so my code is broken : setDefaultCloseOperation is impossible for a JPanel. Since I can't modify the generated code, I was wondering : is there a way to make Netbeans understand I changed my mind, and regenerate the code ? I'm rethinking the design of my GUI. I designed