old_contents: import 'core-js/es6/symbol';
  
  // TODO: Need better, more complete, and more methodical key definitions
  
  const Keys = {
    backspace: 8,
    del:       46,
    delete:    46,
    tab:       9,
    enter:     13,
    'return':  13,
    esc:       27,
    space:     32,
    left:      37,
    up:        38,
    right:     39,
    down:      40,
    ';':       186,
    '=':       187,
    ',':       188,
    '-':       189,
    '.':       190,
    '/':       191,
    '`':       192,
    '[':       219,
    '\\':      220,
    ']':       221
  };
  
  // Add uppercase versions of keys above for backwards compatibility
  Object.keys( Keys ).forEach( key => Keys[ key.toUpperCase() ] = Keys[ key ] );
  
  '0123456789'.split( '' ).forEach( ( num, index ) => Keys[ num ] = index + 48 );
  
  'ABCDEFGHIJKLMNOPQRSTUVWXYZ'.split( '' ).forEach( ( letter, index ) => {
    Keys[letter] = index + 65;
    Keys[letter.toLowerCase()] = index + 65;
  });
  
  // fn keys
  [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12].forEach( ( item, index ) => Keys[ `f${ index }` ] = 111 + index );
  
  export const modifiers = {
    control: 'ctrl',
    ctrl:    'ctrl',
    shift:   'shift',
    meta:    'meta',
    cmd:     'meta',
    command: 'meta',
    option:  'alt',
    alt:     'alt'
  };
  
  export const ALL_KEYS = Symbol('ALL_KEYS')
  
  export const ALL_PRINTABLE_KEYS = Symbol('ALL_PRINTABLE_KEYS')
  
  export default Keys;
  
new_contents: import 'core-js/es6/symbol';
  
  // TODO: Need better, more complete, and more methodical key definitions
  
  const Keys = {
    backspace: 8,
    del:       46,
    delete:    46,
    tab:       9,
    enter:     13,
    'return':  13,
    esc:       27,
    space:     32,
    page_up:   33,
    page_down: 34,
    end:       35,
    home:      36,
    left:      37,
    up:        38,
    right:     39,
    down:      40,
    ';':       186,
    '=':       187,
    ',':       188,
    '-':       189,
    '.':       190,
    '/':       191,
    '`':       192,
    '[':       219,
    '\\':      220,
    ']':       221
  };
  
  // Add uppercase versions of keys above for backwards compatibility
  Object.keys( Keys ).forEach( key => Keys[ key.toUpperCase() ] = Keys[ key ] );
  
  '0123456789'.split( '' ).forEach( ( num, index ) => Keys[ num ] = index + 48 );
  
  'ABCDEFGHIJKLMNOPQRSTUVWXYZ'.split( '' ).forEach( ( letter, index ) => {
    Keys[letter] = index + 65;
    Keys[letter.toLowerCase()] = index + 65;
  });
  
  // fn keys
  [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12].forEach( ( item, index ) => Keys[ `f${ index }` ] = 111 + index );
  
  export const modifiers = {
    control: 'ctrl',
    ctrl:    'ctrl',
    shift:   'shift',
    meta:    'meta',
    cmd:     'meta',
    command: 'meta',
    option:  'alt',
    alt:     'alt'
  };
  
  export const ALL_KEYS = Symbol('ALL_KEYS')
  
  export const ALL_PRINTABLE_KEYS = Symbol('ALL_PRINTABLE_KEYS')
  
  export default Keys;
  
subject: Add pageUp, PageDown, home, end