Odoo - prevent button from closing wizard

Question

I have a transient model that serves as a dialog. In my form view I have a button like this:

Answer 1

The simplest this to do is :

@api.multi
def null_action(self):
    return {
        "type": "set_scrollTop",
    }

As the type is used to call any method on the class ActionManager (javascript)

It's better than "type": "ir.actions.do_nothing" which generate an exception (this attribute doesn't exist)