@ -30,7 +30,7 @@ def _dfs_explore(program, callback):
successors = generator.expand()
assert len(successors) <= 1
for choice in successors:
for state_id, _prob in choice:
for state_id, _prob in choice.distribution:
queue.push(state_id)
current_state_id = queue.pop()
if current_state_id is None: