old_contents: const nope = method => `Cannot use fs.${method} inside browser`;
  
  export const isFile = () => false;
  export const readdirSync = nope( 'readdirSync' );
  export const readFileSync = nope( 'readFileSync' );
  export const writeFile = nope( 'writeFile' );
  
new_contents: const nope = method => `Cannot use fs.${method} inside browser`;
  
  export const lstatSync = nope( 'lstatSync' );
  export const readdirSync = nope( 'readdirSync' );
  export const readFileSync = nope( 'readFileSync' );
  export const realpathSync = nope( 'realpathSync' );
  export const writeFile = nope( 'writeFile' );
  
subject: fix browser version