NS_NOTYETIMPLEMENTED("write me!"); return NS_ERROR_NOT_IMPLEMENTED;
NS_PRECONDITION(aOwnerDocument != nsnull, "null ptr"); if (! aOwnerDocument) return NS_ERROR_NULL_POINTER;  *aOwnerDocument = nsnull; return NS_OK;
XULDocumentImpl::GetOwnerDocument(nsIDOMDocument** aOwnerDocument){    NS_NOTYETIMPLEMENTED("write me!");    return NS_ERROR_NOT_IMPLEMENTED;}