// with 2 foreach and filter in between
lpt = new LogicalPlanTester(pc);
lpt.buildPlan("a = load 'd.txt' as (id, v1, v5, v3, v4, v2);");
lpt.buildPlan("b = foreach a generate v2, v5, v4;");
lpt.buildPlan("c = filter b by v2 != NULL;");
lpt.buildPlan("d = foreach c generate v5, v4;");
plan = lpt.buildPlan("store d into 'empty';");
newLogicalPlan = migratePlan(plan);
optimizer = new MyPlanOptimizer(newLogicalPlan, 3);