Make it explicit in the TabularPolicy that one should not iterate over it to traverse the tree.
Make it explicit in the TabularPolicy that one should not iterate over it to traverse the tree.

PiperOrigin-RevId: 288462481
Change-Id: I9fda3b35ae5fd16c8d90247d62900ed7790ad664

deepmind/open_spiel,deepmind/open_spiel,deepmind/open_spiel,deepmind/open_spiel,deepmind/open_spiel,deepmind/open_spiel