Overload a method for a new button in Form extension

 This can be used as a copy-paste pattern, when you need to change a standard method for new form controls added as a form extensions.

At the form initialization step we can overload any form control methods with registerOverrideMethod.

[ExtensionOf(formStr(<FormName>))]
public final class my<FormName>_MyNewButton_Extension
{
   public void init()
    {
        next init();
		// MyNewButton button added in an extension to <FormName>
        FormButtonControl myButton = this.design().controlName(formControlStr(<FormName>, myNewButton));
		// Here we can overload its standard clicked() method in run-time		
        myButton.registerOverrideMethod(methodStr(FormButtonControl, clicked), formMethodStr(<FormName>, myNewButtonClicked), this);
    }

    public void myNewButtonClicked(FormButtonControl _sender)
    {
		<run some logic>
        _sender.clicked();
    }
}

Check this article for more complicated scenario https://alexvoy.blogspot.com/2018/09/lookup-and-modified-methods-for.html