message: Returned old value if unchanged
diff: @@ -35,6 +35,7 @@ const Stack = ({ children, ...props }) => {
  stateNavigator.onBeforeNavigate(validateNavigation);
  return newStates;
  }
  + return oldStates;
  });
  return () => stateNavigator.offBeforeNavigate(validateNavigation);
  }, [ children ]);
  