public IActionResult Transfer(TransactionTransferViewModel viewModel)
        {
            var account = _repository.GetAccountById(viewModel.AccountId);

            if (_repository.CheckIfSufficientBalance(viewModel.AmountToTransfer, account.Balance) == false)
            {
                ModelState.AddModelError("AmountToTransfer", "There's not enough money on this account for this transfer");
            }
            else
            {
                if (ModelState.IsValid)
                {
                    _repository.Transfer(viewModel.AccountId, viewModel.ToAccountId, viewModel.AmountToTransfer);
                    return(RedirectToAction("Index"));
                }
            }
            return(View(viewModel));
        }
        public IActionResult Transfer()
        {
            var viewModel = new TransactionTransferViewModel();

            return(View(viewModel));
        }