This is a testharness.js-based test.
[FAIL] el-tbody
  assert_equals: <tbody data-testname="el-tbody" data-expectedrole="rowgroup" class="ex">\n    <tr>\n      <th>1</th>\n      <td>2</td>\n      <td>3</td>\n    </tr>\n    <tr>\n      <th>4</th>\n      <td>5</td>\n      <td>6</td>\n    </tr>\n  </tbody> expected "rowgroup" but got "none"
Harness: the test ran to completion.