NS_ADDREF(element);
NS_IF_ADDREF(element);
_hashEnumerateCopy(PLHashEntry *he, PRIntn i, void *arg){    nsHashtable *newHashtable = (nsHashtable *)arg;    nsISupports* element = NS_STATIC_CAST(nsISupports*, he->value);    NS_ADDREF(element);    newHashtable->Put((nsHashKey*)he->key, he->value);    return HT_ENUMERATE_NEXT;}