PaperRadioGroup have incorrectly behaviour if created dynamic

[hoppermann]

If you add a PaperRadioGroup dynamic, the containing PaperRadioButtons behave as if they are not in a group.

example project

[a-dyachenko]

I have exactly same issue when dynamically or statically adding PaperRadioGroup and then dynamically adding PaperRadioButton to this group. PaperRadioButton values are not accessible from the group either.