code: @Deployment public void testSetServiceResultToProcessVariablesWithSkipExpression(){
    Map<String,Object> variables=new HashMap<String,Object>();
    variables.put("okReturningService",new OkReturningService());
    variables.put("_ACTIVITI_SKIP_EXPRESSION_ENABLED",false);
    ProcessInstance pi=runtimeService.startProcessInstanceByKey("setServiceResultToProcessVariablesWithSkipExpression",variables);
    assertEquals("ok",runtimeService.getVariable(pi.getId(),"result"));
    Map<String,Object> variables2=new HashMap<String,Object>();
    variables2.put("okReturningService",new OkReturningService());
    variables2.put("_ACTIVITI_SKIP_EXPRESSION_ENABLED",true);
    variables2.put("skip",true);
    ProcessInstance pi2=runtimeService.startProcessInstanceByKey("setServiceResultToProcessVariablesWithSkipExpression",variables2);
    assertEquals(null,runtimeService.getVariable(pi2.getId(),"result"));
  }
  