plan.connect(load1, split1) ;
plan.connect(split1, splitOutput1) ;
plan.connect(split1, splitOutput2) ;
CompilationMessageCollector collector = new CompilationMessageCollector() ;
TypeCheckingRelVisitor typeChecker = new TypeCheckingRelVisitor(plan, collector);
typeChecker.visit();
printMessageCollector(collector) ;
//printTypeGraph(plan) ;
if (collector.hasError()) {
throw new AssertionError("Expect no error") ;