public void CountryRegionName_CountryRegionFound_ReturnsName(
            List <CountryRegion> list
            )
        {
            //Act
            string result = AddressExtensions.CountryRegionName(
                list[0].CountryRegionCode, list);

            //Assert
            result.Should().Be(list[0].Name);
        }
        public void CountryRegionName_CountryRegionNotFound_ThrowArgumentNullException(
            CountryRegion countryRegion
            )
        {
            //Act
            Func <string> func = () => AddressExtensions.CountryRegionName(
                countryRegion.CountryRegionCode,
                new List <CountryRegion>()
                );

            //Assert
            func.Should().Throw <ArgumentNullException>()
            .WithMessage("Value cannot be null. (Parameter 'country')");
        }