int sessionId = service.getSessionId();
StartProcessCommand startProcessCommand = new StartProcessCommand();
startProcessCommand.setProcessId( "org.drools.test.ProcessSubProcess" );
RuleFlowProcessInstance processInstance = (RuleFlowProcessInstance) service.execute( startProcessCommand );
log.info( "Started process instance {}", processInstance.getId() );
long processInstanceId = processInstance.getId();
TestWorkItemHandler handler = TestWorkItemHandler.getInstance();
WorkItem workItem = handler.getWorkItem();