How to Hide the "Collapse-O-Matic" Admin Menu

function plt_hide_jquery_collapse_o_matic_menus() {
	//Hide the "Settings → Collapse-O-Matic" menu.
	remove_submenu_page('options-general.php', 'collapse-o-matic-options');
}

add_action('admin_menu', 'plt_hide_jquery_collapse_o_matic_menus', 11);

Where do I put this code?