code: def _process_key(evt):
      
      key = evt.GetKeyCode()
      if key in KEYMAP:
          return KEYMAP[key], ''
      if 97 <= key <= 122:
          key -= 32
      if key >= 32 and key <= 127:
          return keys.Key(chr(key)), chr(key)
      else:
          return None, None
docs: Helper to convert from wx keycode to vispy keycode