TaskApplication getTaskApplication() {
    return appDesc -> {
      appDesc.withInputStream(input1Descriptor)
          .withInputStream(input2Descriptor)
          .withInputStream(intermediateInputDescriptor)
          .withOutputStream(intermediateOutputDescriptor)
          .withOutputStream(outputDescriptor)
          .withTaskFactory(() -> new IdentityStreamTask());
    };
  }
Unit test base class to set up commonly used test application and configuration.
samza-core/src/test/java/org/apache/samza/execution/ExecutionPlannerTestBase.java