private String @Nullable[] getActionsIds(int modifiers) {
    final KeymapManager manager = KeymapManager.getInstance();
    if (manager == null)
      return null;

    final @NotNull Keymap keymap = manager.getActiveKeymap();

    String[] result = myCache.get(modifiers);
    if (result != null) {
      return result;
    }
    KeyStroke keyStroke = KeyStroke.getKeyStroke(KeyEvent.VK_F1 + myFN - 1, modifiers);
    result = keymap.getActionIds(keyStroke);
    myCache.put(modifiers, result);
    return result;
  }
private String @Nullable[] getActionsIds(int modifiers)