public ProcessorTopology buildSubtopology(final TaskId task) {
        final InternalTopologyBuilder builder = lookupBuilderForTask(task);
        return builder.buildSubtopology(task.subtopology());
    }
@return the {@link ProcessorTopology subtopology} built for this task, guaranteed to be non-null

@throws UnknownTopologyException  if the task is from a named topology that this client isn't aware of
streams/src/main/java/org/apache/kafka/streams/processor/internals/TopologyMetadata.java