static int showWindowInTopRightCorner_x = 25;
static int showWindowInTopRightCorner_y = 5;

static JWindow showWindowInTopRightCorner(final JComponent c) {
  if (isHeadless()) null;
  ret swing(func -> JWindow {
    JWindow window = makeWindow(c);
    window.pack();
    Rectangle r = maxWindowBounds();
    window.setBounds(r.x+r.width-window.getWidth()-showWindowInTopRightCorner_x, r.y+showWindowInTopRightCorner_y, window.getWidth(), window.getHeight());
    window.setAlwaysOnTop(true);
    window.setVisible(true);
    ret window;
  });
}

Began life as a copy of #1015133