@isTest
static void whenStartSchedulerIsInvokedANewJobIsStarted() {
    List<AsyncApexJob> apexjobs = [select id, ApexClass.Name From AsyncApexJob where ApexClass.Name = :BatchMessageQueueProcessor.class.getName() ];
    integer nrJobsBefore = apexjobs.size();
    Test.startTest();
    MessageQueueUtils.StartScheduler();
    Test.stopTest();
    apexjobs = [select id, ApexClass.Name From AsyncApexJob where ApexClass.Name = :BatchMessageQueueProcessor.class.getName() ];
    integer nrJobsAfter = apexjobs.size();
    system.assertEquals(nrJobsBefore + 1, nrJobsAfter, 'A new job must have been created');
}