$wnckWin->get_client_window_geometry();
$wnckWin->set_geometry(
    'WNCK_WINDOW_GRAVITY_CURRENT',
        [
            'WNCK_WINDOW_CHANGE_X',       
            'WNCK_WINDOW_CHANGE_Y',
            'WNCK_WINDOW_CHANGE_WIDTH',
            'WNCK_WINDOW_CHANGE_HEIGHT',
        ],
     $x,
     $y,
     $width,
     $height,
);