m show up as File objects in the "formData" IDL attribute`);
}

test(() => {
  let listener1ok = false;
  let listeern2ok = false;
  let form = populateForm('<input name=n1 value=v1>');
  form.addEventListener('formdata', e => {
    listener1ok = e.formData.get('n1') == 'v1';
    e.formData.append('h1', 'vh1');
    e.formData.append('h2', 'vh2');
  });
  form.addEventListener('formdata', e => {
    if (e.formData.get('h1') == 'vh1' && e.formData.get('h2') == 'vh2')
      listener2ok = true;
  });
  form.sub