@SuppressWarnings("unchecked")
    void unite(final T id1, final T... idList) {
        for (final T id2 : idList) {
            unitePair(id1, id2);
        }
    }
@throws NoSuchElementException if the parent of this node is null
streams/src/main/java/org/apache/kafka/streams/processor/internals/QuickUnion.java