nsresult rv;
XULContentSinkImpl::CreateElement(nsINodeInfo *aNodeInfo,                                  nsXULPrototypeElement** aResult){    nsresult rv;    nsXULPrototypeElement* element = new nsXULPrototypeElement(/* line number */ -1);    if (! element)        return NS_ERROR_OUT_OF_MEMORY;    element->mNodeInfo    = aNodeInfo;    element->mDocument    = mPrototype;    nsCOMPtr<nsINameSpace> ns;    rv = GetTopNameSpace(address_of(ns));    if (NS_SUCCEEDED(rv)) {        element->mNameSpace = ns;    }    *aResult = element;    return NS_OK;}