Test the Location of the current Page

Vaadin 6 / 7 / 8 Framework UI
1

I’m redirecting with following statement to a new page:
getParent().getPage().setLocation(“http://www.test.de”);

How can I test in a JUnit-Test that the redirection works fine / was done?
Calling getParent() or getPage() isn’t possible in a JUnit-Test…