text: // @flow
  export type ReactElement = any;
  
  export type TraversalDirection = 'up' | 'down';
  export type OnAnimationEnd = ({|
    traversalDirection: TraversalDirection,
  |}) => void;
  export type Stack = Array<Array<ReactElement>>;
  
  export type ContainerNestedNavigationPageState = {|
    isEntering: boolean,
    isLeaving: boolean,
  |};
  