static void Main(string[] args)
{
//Create a Product with Out Of Stock Status
Subject RedMI = new Subject("Red MI Mobile", 10000, "Out Of Stock");
//User Anurag will be created and user1 object will be registered to the subject
Observer user1 = new Observer("Anurag", RedMI);
//User Pranaya will be created and user1 object will be registered to the subject
Observer user2 = new Observer("Pranaya", RedMI);
//User Priyanka will be created and user3 object will be registered to the subject
Observer user3 = new Observer("Priyanka", RedMI);
Console.WriteLine("Red MI Mobile current state : " + RedMI.getAvailability());
Console.WriteLine();
// Now product is available
RedMI.setAvailability("Available");
Console.Read();
}