require(['base/js/namespace', 'jquery', 'base/js/events'], function(IPython, $, events){
    events.on('app_initialized.NotebookApp', function(){
        $('#header-container').hide();
        $('.header-bar').hide();
        $('div#maintoolbar').hide();
        IPython.menubar._size_header();
    })
    console.log('Header and toolbar should be hidden by default now')
})