FlowElementGraph elementGraph = new HashJoinMergeIntoHashJoinStreamedStreamedMergeGraph();
// FlowElementGraph elementGraph = new HashJoinAroundHashJoinLeftMostGraph();
RuleResult ruleResult = new RuleExec( ruleRegistry ).executeRulePhase( PlanPhase.PreResolveAssembly, plannerContext, new RuleResult( elementGraph ) );
FlowElementGraph flowElementGraph = ruleResult.getAssemblyGraph();
flowElementGraph.writeDOT( getPlanPath() + "/mergejoin.dot" );
ContractedTransformer transformer = new ContractedTransformer( new TestNoGroupTapExpressionGraph() );
Transformed<ElementGraph> transformed = transformer.transform( plannerContext, flowElementGraph );