code: @Deployment public void testLogger(){
    setCustomLogger();
    try {
      runtimeService.startProcessInstanceByKey("testLoggerProcess");
      fail("Expected exception");
    }
   catch (  Exception e) {
    }
    String messages=console.toString();
    assertTrue(messages.contains("ProcessDefinitionId=" + TestService.processDefinitionId));
    assertTrue(messages.contains("executionId=" + TestService.executionId));
    assertTrue(messages.contains("mdcProcessInstanceID=" + TestService.processInstanceId));
    assertTrue(messages.contains("mdcBusinessKey=" + (TestService.businessKey == null ? "" : TestService.businessKey)));
    console.clear();
    unsetCustomLogger();
    try {
      runtimeService.startProcessInstanceByKey("testLoggerProcess");
      fail("Expected exception");
    }
   catch (  Exception e) {
    }
    assertFalse(console.toString().contains("ProcessDefinitionId=" + TestService.processDefinitionId));
  }
  