private static string IsGood(PersonModel person, PetModel pet)
        {
            //returns true if one prefrence matches and no overrides match
            bool preference = person.PreferredClassification == pet.Classification || person.PreferredType == pet.Type || person.PreferredWeight == pet.GetWeightClass();
            bool overrides  = person.checkOverrides(pet);

            return((preference && (!overrides)) ? "good": "bad");
        }