public Operation createOperation(OperationType operationType, BigDecimal cost) {
   Operation operation = new Operation();
   operation.account = persistAccount(new BigDecimal(1000L));
   operation.cost = cost;
   operation.date = new Date();
   operation.description = "Test description";
   operation.operationType = operationType;
   Set<Label> labelSet = new HashSet<>();
   labelSet.add(persistLabel());
   operation.labels = labelSet;
   return operation;
 }
 public List<Operation> persistOperationList() {
   Account account = persistAccount(new BigDecimal(1000L));
   List<Operation> operations = new ArrayList<>();
   for (int i = 0; i < 10; i++) {
     Operation operation = new Operation();
     operation.operationType = OperationType.expense;
     operation.cost = new BigDecimal(100L);
     operation.date = new Date();
     operation.account = account;
     manager.persist(operation);
     operations.add(operation);
   }
   manager.flush();
   return operations;
 }