private static void Main(string[] args)
{
Console.WriteLine("Observer Pattern");
// Subject
var savingsAccount = new BankAccount("Savings Account");
// Create Concrete Observers
var homer = new BankClient("Homer Simpson", savingsAccount);
var marge = new BankClient("Marge Simpson", savingsAccount);
// Attach observers
savingsAccount.Attach(homer);
savingsAccount.Attach(marge);
// Lets observe the transactions
homer.Deposit(100);
marge.Withdraw(50);
homer.Withdraw(51);
marge.Deposit(-100);
// Final value should be $350
marge.Deposit(300);
Console.ReadLine();
}