@Test
public void testNoMostRecentIdGetOperationReturnNull() {

    // Given
    when(memcacheService.get(MemcacheKey.DB_OPERATION_COUNTER.getName())).thenReturn(null);
    // when
    List<DbOperationRecordDto> results = operationService.getOperations(0L, 1);
    // then
    verify(memcacheService).get(MemcacheKey.DB_OPERATION_COUNTER.getName());
    assertNull(results);
}