public class BankAccount {

   private double interestRate;
   private string owner;
   private double balance;

   // ...

   public void Withdraw (double amount) {
      if (!AccountOK)
        ComplainAboutNonValidAccount();
      else if (!this.EnoughMoney(amount))
        ComplainAboutMissingMoney();
      else
        balance -= amount;
   }

   public void Deposit (double amount) {
      if (amount >= 10000000)
        CheckIfMoneyHaveBeenStolen();
      else if (!AccountOK)
        ComplainAboutNonValidAccount();
      alse balance += amount;
   }
}