code: function assertNodeIsElement(node) {
    if (googAsserts.ENABLE_ASSERTS && !isNodeElement(node)) {
      googAsserts.fail(
          'Expected Node of type Element but got Node of type %s',
          getNodeType(node));
    }
    return /** @type {!Element} */ (node);
  }
docs: Asserts that a Node is an Element, without falling prey to things like
  <form><input name="nodeType"></form>.
  @param {!Node} node
  @return {!Element}