<script src="../testing.js"></script>
<script id=documentType>
  let dt1 = document.implementation.createDocumentType('qname1', 'pid1', 'sys1');
  let dt2 = document.implementation.createDocumentType('qname2', 'pid2', 'sys2');
  let dt3 = document.implementation.createDocumentType('qname1', 'pid1', 'sys1');
  testing.expectEqual(true, dt1.isEqualNode(dt1));
  testing.expectEqual(true, dt1.isEqualNode(dt3));
  testing.expectEqual(false, dt1.isEqualNode(dt2));
  testing.expectEqual(false, dt2.isEqualNode(dt3)