AsyncStorage
type AsyncStorage = { getItem: (key: string) => Promise<null | string>; removeItem: (key: string) => Promise<void>; setItem: (key: string, value: string) => Promise<void>;};
function getItem(key: string): Promise<null | string>;
function removeItem(key: string): Promise<void>;
function setItem(key: string, value: string): Promise<void>;