Revert "Use new-style types for core properties."
Revert "Use new-style types for core properties."

This reverts commit 94508846848509808464cf788641dfda7379335e.
Reverting "Use new-style types for core properties."

rburchell/ck,rburchell/ck,rburchell/ck,rburchell/ck,rburchell/ck