@Test
void shouldForbidDuplications()
        throws IOException
{

    assertSingleInitialInstance();
    CronTaskConfigurationDto newDto = new CronTaskConfigurationDto();
    newDto.setJobClass(TestJavaCronJob.class.getName());
    newDto.setProperties(
            ImmutableMap.of(PROPERTY_REPOSITORY_ID, REPOSITORY_RELEASES, PROPERTY_STORAGE_ID, STORAGE_0));
    cronTaskDataService.save(newDto);
    assertSingleInitialInstance();
}