public void SubscriptionsService_DeletePurchase_calls_Delete_method()
{
int id = 12;
bool isDeleteCalled = false;
var mock = new Mock <IUnitOfWork>();
mock.Setup(a => a.Purchases.Delete(id)).Callback(() => isDeleteCalled = true);
service = new SubscriptionsService(mock.Object);
service.DeletePurchase(id);
Assert.IsTrue(isDeleteCalled);
}