So I went through your code.
First off, you initialised the wrong package.
self.init("pyside_example", None, None)
you want rvTestUi in there. I’m not sure how that influences your package itself. It just throws an error for me, if I want to load the pyside_example package too.
Other than that your code is fine, it’s just not finished.
For your dialog to do something it needs to be shown.
The pyside_example has activate and deactivate methods for that.
If you add them to your code, the dialog pops up right away.
And I really would change the imports if you continue to add to your code. It will be so much easier to debug and so much cleaner.