Xamarin.Forms: How do I change CurrentPage of a TabbedPage to a Page that is not a child?

Hey guys.

I'm working on a Xamarin.Forms project where I need to be able to set the CurrentPage of a TabbedPage to a Page that is not a child of the TabbedPage.

Setting the CurrentPage to one of the children of the TabbedPage like this works:

CurrentPage = Children[1];

But nothing happens when I try to set the CurrentPage to a new Page. (A page that is not a child of the TabbedPage and therefore not one of the tabs in the tab bar):

CurrentPage = new Test();

Is it possible to do something like this? The goal is being able to have the tab bar remain while navigating to other Pages that are not part of the tab bar.

An example of this behavior can be seen when using the Google+ app. When you navigate to a Page not present in the tab bar using the hamburger menu, the tab bar remains on the new page, but without any of the tabs in the tab bar being highlighted.

Thanks in advance!