NS_PRECONDITION(resource != nsnull, "null ptr"); if (! resource) return NS_ERROR_NULL_POINTER;
ServiceImpl::UnregisterResource(nsIRDFResource* resource){    nsresult rv;    const char* uri;    if (NS_FAILED(rv = resource->GetValue(&uri)))        return rv;    PL_HashTableRemove(mResources, uri);    return NS_OK;}