@Test
  public void testCreateJobGraphForTaskApplication() {
    TaskApplicationDescriptorImpl taskAppDesc = mock(TaskApplicationDescriptorImpl.class);
    // add interemediate streams
    String intermediateStream1 = "intermediate-stream1";
    String intermediateBroadcast = "intermediate-broadcast1";
    // intermediate stream1, not broadcast
    GenericInputDescriptor<KV<Object, Object>> intermediateInput1 = system1Descriptor.getInputDescriptor(
        intermediateStream1, new KVSerde<>(new NoOpSerde(), new NoOpSerde()));
    GenericOutputDescriptor<KV<Object, Object>> intermediateOutput1 = system1Descriptor.getOutputDescriptor(
        intermediateStream1, new KVSerde<>(new NoOpSerde(), new NoOpSerde()));
    // intermediate stream2, broadcast
    GenericInputDescriptor<KV<Object, Object>> intermediateBroacastInput1 = system1Descriptor.getInputDescriptor(
        intermediateBroadcast, new KVSerde<>(new NoOpSerde<>(), new NoOpSerde<>()));
    GenericOutputDescriptor<KV<Object, Object>> intermediateBroacastOutput1 = system1Descriptor.getOutputDescriptor(
        intermediateBroadcast, new KVSerde<>(new NoOpSerde<>(), new NoOpSerde<>()));
    inputDescriptors.put(intermediateStream1, intermediateInput1);
    outputDescriptors.put(intermediateStream1, intermediateOutput1);
    inputDescriptors.put(intermediateBroadcast, intermediateBroacastInput1);
    outputDescriptors.put(intermediateBroadcast, intermediateBroacastOutput1);
    Set<String> broadcastStreams = new HashSet<>();
    broadcastStreams.add(intermediateBroadcast);

    when(taskAppDesc.getInputDescriptors()).thenReturn(inputDescriptors);
    when(taskAppDesc.getInputStreamIds()).thenReturn(inputDescriptors.keySet());
    when(taskAppDesc.getOutputDescriptors()).thenReturn(outputDescriptors);
    when(taskAppDesc.getOutputStreamIds()).thenReturn(outputDescriptors.keySet());
    when(taskAppDesc.getTableDescriptors()).thenReturn(Collections.emptySet());
    when(taskAppDesc.getSystemDescriptors()).thenReturn(systemDescriptors);
    when(taskAppDesc.getIntermediateBroadcastStreamIds()).thenReturn(broadcastStreams);
    doReturn(MockTaskApplication.class).when(taskAppDesc).getAppClass();

    Map<String, String> systemStreamConfigs = new HashMap<>();
    inputDescriptors.forEach((key, value) -> systemStreamConfigs.putAll(value.toConfig()));
    outputDescriptors.forEach((key, value) -> systemStreamConfigs.putAll(value.toConfig()));
    systemDescriptors.forEach(sd -> systemStreamConfigs.putAll(sd.toConfig()));

    ExecutionPlanner planner = new ExecutionPlanner(config, streamManager);
    JobGraph jobGraph = planner.createJobGraph(taskAppDesc);
    assertEquals(1, jobGraph.getJobNodes().size());
    assertTrue(jobGraph.getInputStreams().stream().map(edge -> edge.getName())
        .filter(streamId -> inputDescriptors.containsKey(streamId)).collect(Collectors.toList()).isEmpty());
    Set<String> intermediateStreams = new HashSet<>(inputDescriptors.keySet());
    jobGraph.getInputStreams().forEach(edge -> {
      if (intermediateStreams.contains(edge.getStreamSpec().getId())) {
        intermediateStreams.remove(edge.getStreamSpec().getId());
      }
    });
    assertEquals(new HashSet<>(Arrays.asList(intermediateStream1, intermediateBroadcast)), intermediateStreams);
  }
A special example of stream-table join where a stream is joined with a table, and the result is
sent to the same table. This example is necessary to ensure {@link ExecutionPlanner} does not
get stuck traversing the virtual cycle between stream-table-join and send-to-table operator specs
indefinitely.

The reason such virtual cycle is present is to support computing partitions of intermediate
streams participating in stream-table joins. Please, refer to SAMZA SEP-16 for more details.
samza-core/src/test/java/org/apache/samza/execution/TestExecutionPlanner.java