/// <summary>
/// The Account balance is the sum of all Ledger amounts.
/// </summary>
public static decimal Balance(this Account.LedgersRole ledgers)
{
return(ledgers.Sum(e => e.Amount));
}
// Use case implementations of the Account.
/// <summary>
/// Changing the account amount means adding an entry to the Ledgers.
/// </summary>
public static void AddEntry(this Account.LedgersRole ledgers, string message, decimal amount)
{
ledgers.Add(new LedgerEntry {
Message = message, Amount = amount
});
}
