setState((state) => {
        const value = stateLamda(state.value);
        AsyncStorage.setItem(this._cacheKey, JSON.stringify(value));
        return {value};
      });
    };
    render(): React.Node {
      return (
        <Component
          {...this.props}
          persister={{
            state: this.state.value,
            setState: this._passSetState,
          }}
        />
      );
    }
A simple container for persisting some state and passing it into the wrapped component as
`props.persister.state`. Update it with `props.persister.setState`. The component is initially
rendered using `getInitialState` in the spec and is then re-rendered with the persisted data
once it's fetched.

This is currently tied to RNTester because it's generally not good to use AsyncStorage like
this in real apps with user data, but we could maybe pull it out for other internal settings-type
usage.