CachedXPathAPI needs to be discarded when new Node is created, or only if Document tree is changed?

Suppose we are using a CachedXPathAPI object.  We then use
Node.createClone() or Document.newElement() to create a new Element that
is owned by the Document, but has no parent and is not in the Document
tree.  Is the CachedXPathAPI object we are using still valid?  Or is the
Document now considered "changed", and we need to create a new
CachedXPathAPI object?

 

Thanks, 

Gary