import ThemeContext from 'react-theme-context' ; import dark from './dark' ; /**
 * A singleton class for storing the app ThemeContext.
 */ export default class AppTheme { private static _context : ThemeContext < typeof dark > ; private constructor ( ) { } public static context ( initialTheme = dark ) { return this . _context || ( this . _context = new ThemeContext ( initialTheme ) ) ; } }