newPreoptimizedPlan = new LogicalPlan( plan );
if (pigContext.inIllustrator) {
// disable all PO-specific optimizations
POOptimizeDisabler pod = new POOptimizeDisabler( plan );
pod.visit();
}
DanglingNestedNodeRemover DanglingNestedNodeRemover = new DanglingNestedNodeRemover( plan );
DanglingNestedNodeRemover.visit();