message: Prepended index so keys are unique
diff: @@ -25,11 +25,11 @@ class NavigationStack extends React.Component<NavigationStackProps, NavigationSt
  if (stateNavigator === prevStateNavigator)
  return null;
  var {oldState, state, crumbs, nextCrumb} = stateNavigator.stateContext;
  - var currentKeys = crumbs.concat(nextCrumb).map(({state}) => state.key);
  + var currentKeys = crumbs.concat(nextCrumb).map(({state}, i) => `${i}_${state.key}`);
  var newKeys = currentKeys.slice(prevKeys.length);
  var keys = prevKeys.slice(0, currentKeys.length).concat(newKeys);
  if (prevKeys.length === keys.length && oldState !== state)
  - keys[keys.length - 1] = state.key;
  + keys[keys.length - 1] = `${keys.length - 1}_${state.key}`;
  return {keys, stateNavigator};
  }
  componentDidUpdate() {
  