I have found that if UsableDuringInitialization(true) object has more than one property set in XAML, such an object would be attached to a parent collection multiple times. Unfortunately, my previous test did not cover this scenario. So this PR includes both the updated test, and the fix.
I have found that if UsableDuringInitialization(true) object has more than one property set in XAML, such an object would be attached to a parent collection multiple times. Unfortunately, my previous test did not cover this scenario. So this PR includes both the updated test, and the fix.