@Override
 public List<CfPeriod> findPeriods(String filter, String[] funds, Integer offset, Integer limit) {
   return periodDao.find(filter, funds, offset, limit);
 }
 @Override
 public List<CfPeriod> findPeriods(CfCostCenter costCenter, Integer offset, Integer limit) {
   return periodDao.find(costCenter, offset, limit);
 }
 @Override
 public List<CfPeriod> findPeriods(Integer offset, Integer limit) {
   return periodDao.find(offset, limit);
 }