libGDX MENU button

Newbie & Debugging Questions
#1

I have a game, in which are some function buttons, which defined as ImageButtons. I have some other shapes, which are Sprites. On each type of elements have own type of listeners. I set active function buttons’ Stage by MENU button. It isn’t practical, because newer devices haven’t MENU button.

@Override
public boolean keyDown(int keycode) {
    if ((keycode == Keys.M) || (keycode == Keys.MENU)) {
       // some code
}

What do you think, how can I replace this “method”?