slot');
  var c3 = select.$.select.$.select.root.querySelector('slot');
  assert.equal(c1.getAttribute('name'), 's1');
  assert.equal(c2.getAttribute('name'), 's2');
  assert.equal(c3.getAttribute('name'), 's3');
  // var ip$ = [c1, c2, c3];
  assert.equal(child.className, 'select-child');
  assert.equal(allInsertionPoints(child).length, 0);
  child.slot = 's1';
  flush();
  assert.deepEqual(allInsertionPoints(child), [c1]);
  child.slot = 's2';
  c1.setAttribute('name', 's2');
  c1.slot = 's2';
  flush();
