public void visitLOForEach(LOForEach foreach) throws IOException {
Set<Long> output = setOutputUids(foreach);
LogicalPlan innerPlan = foreach.getInnerPlan();
LOGenerate gen = (LOGenerate)innerPlan.getSinks().get(0);
gen.annotate(OUTPUTUIDS, output);
ColumnDependencyVisitor v = new ColumnDependencyVisitor(innerPlan);
v.visit();
Set<Long> input = new HashSet<Long>();