  function assertNodes(expected, actual) {
    actual = actual.map((n) => n.id || n.textContent)
    testing.expectEqual(expected, actual);
  }

  for (let idx of [1, 2, 3, 4]) {
    const lp = $(`#lp${idx}`);
    const slot = lp.shadowRoot.querySelector('slot');

    assertNodes([], slot.assignedNodes());
    assertNodes([], slot.assignedNodes({}));
    assertNodes([], slot.assignedNodes({flatten: false}));
    if (lp.getAttribute('mode') === '1') {
      assertNodes(['hello'], slot.assignedNodes({flatten: