public Animal BuyAnimal <T>(Person person)
{
if (_shelterRepository.IsShelterEmpty())
{
return(null);
}
//throw an exception if invalid kind of animal
if (!d.ContainsValue(typeof(T)))
{
throw new ArgumentException($"Expected {string.Join(", ", d.Keys.ToList())}" +
$" received {typeof(T).Name.ToLower()}");
}
var type = d.FirstOrDefault(x => x.Value == typeof(T)).Value;
return(_purchaseHelper.PurchaseAnimal <T>(person));
}