testMapper2.setInput(input2);
output.addInput(testMapper1);
output.addInput(testMapper2);
Plan plan = new Plan(output);
plan.setDefaultParallelism(DOP);
PactCompiler pc = new PactCompiler(new DataStatistics());
OptimizedPlan op = pc.compile(plan);
NepheleJobGraphGenerator jgg = new NepheleJobGraphGenerator();