public void ValidateApartment_NotEmptyStringReturned() { var apartment = new Apartment() { BedId = 1, RoomId = 1, Id = 1, Clinic = new Clinic1() { Id = 1, Code = "", Name = "Clinic", Address = "Address" } }; string result = ApartmentMethods.ValidateApartment(apartment); Assert.IsNotNullOrEmpty(result); }