Chain of Command at Form button

Hi Friends,

I found this piece of code in google, How to write COC extensions on Form button.

We normally use Pre and Post event handlers but I am trying to understand Chain of Command on Form buttons.

As highlighted in yellow, Do I need to create a separate class for writing some price of code on this button. 

If I have 5 buttons and I want to write COC  then do i need to create 5 classes for these 5 buttons.

**********(All I am talking is considering a form already exist like "SalesTable" form and I want to implement COC on that form buttons , assume 5 buttons. Do I need to proceed

creating 5 classes or any alternative approach exist)*********

Please tell your comments.

[ExtensionOf(formControlStr(MyForm, Button1))]

final class FormButton1_Extension


    public void clicked()


        next clicked();

        // do something here