C# (CSharp) Balances.SingleOrDefault примеры использования

Пример #1

 public AssetBalance GetBalanceByExchange(string exchange)
 {
     return(Balances.SingleOrDefault(x =>
                                     string.Equals(x.Exchange, exchange, StringComparison.InvariantCultureIgnoreCase))
            ?? new AssetBalance
     {
         Exchange = exchange
     });
 }