}
private ShuffleModel shuffle(Class<? extends FlowDescription> aClass) {
StageGraph graph = jfToStageGraph(aClass);
assertThat(graph.getStages().size(), is(1));
StageBlock target = graph.getStages().get(0);
ShuffleAnalyzer analyzer = new ShuffleAnalyzer(environment);
ShuffleModel analyzed = analyzer.analyze(target);
assertThat(environment.hasError(), is(false));
return analyzed;
}