public void SaveNewContract(Contract newContract)
        {
            DbContext.Contracts.Add(newContract);
            DbContext.SaveChanges();

            OrganisationRepository HelperRepository = new OrganisationRepository(DbContext);

            HelperRepository.IncreaseNumberOfContracts(newContract.OrganisationId);
        }
        public void DeleteContract(int contractId)
        {
            Contract contract = FindContractById(contractId);

            DbContext.Contracts.Remove(contract);
            DbContext.SaveChanges();

            OrganisationRepository HelperRepository = new OrganisationRepository(DbContext);

            HelperRepository.DecreaseNumberOfContracts(contract.OrganisationId);
        }