// create a default instance to check account numbers with bank codes
IAccountNumberCheckWithBankCode sut = new AccountNumberCheck();
// first argument is the account number, second is the bank code
// the mapping of the bank code to a check method is done internally via the official bank code list
sut.IsValid(new GermanAccountNumber { AccountNumber = "4234322787", BankCode = "87070000" });

// or shortcut via extension methods
new GermanAccountNumber { AccountNumber = "4234322787", BankCode = "87070000" }).IsValid();

// create a default instance to check credit card numbers
ICreditCardNumberCheck sut = new CreditCardNumberCheck();
// first argument is the credit card number (can include spaces, minus or other non-numeric chars)
// second is a specific credit card network identifier or automatic
sut.IsValid("4234 3227 8778 9876", CreditCardNetwork.Visa);
// or with automatic detection of the credit card network based upon the IIN prefix
sut.IsValid("4234 3227 8778 9876", CreditCardNetwork.Automatic);

// create a default instance of the converter
IIBANConvert sut = new IBANConvert();
// converting
sut.ToIBAN(new GermanAccountNumber { BankCode = "1234 5678", AccountNumber = "9090 1234 00" });
// and back
var nationalAccountNumber = sut.FromIBAN("DE42123456789090123400");