Assert -> throw condition

dom.bs

@@ -2656,7 +2656,8 @@ of a <var>node</var> into a <var>parent</var> before a <var>child</var>, run the
 of a <var>node</var> into a <var>parent</var> before a <var>child</var>, run these steps:
 
 <ol>
- <li><p><a>Assert</a>: <var>node</var> is either an {{Element}} or {{CharacterData}}.</p></li>
+ <li><p>If <var>node</var> is not an {{Element}} or a {{CharacterData}} <a for=/>node</a>, then
+ <a>throw</a> a "{{HierarchyRequestError!!exception}}" {{DOMException}}.</p></li>
 
  <li><p>If <var>parent</var> is not an {{Element}} <a for=/>node</a>, then <a>throw</a> a
  "{{HierarchyRequestError!!exception}}" {{DOMException}}.