private static void updateSize(final AbstractNode node,
                                   final int delta) {
        node.size += delta;

        for (final TopologyDescription.Node predecessor : node.predecessors()) {
            updateSize((AbstractNode) predecessor, delta);
        }
    }
@return names of all source topics, including the application id/named topology prefix for repartition sources
streams/src/main/java/org/apache/kafka/streams/processor/internals/InternalTopologyBuilder.java