CaptureTheFlag | Capture The Flag for drones

I have a question. How do you place a method in the deceleration of an object? Let me explain. What I’m making is a Minecraft network. All of the games we have to offer are their own class.

Example: CaptureTheFlag is its own object but it extends a class called arena.

Every game class extends the Arena class. So when these games are made, they are added to a hashmap (double, arena). When I iterate through these looking for a specific gamemode I need to be able to call the method for that gamemode for the player to join.

Example: CaptureTheFlag.join(player)

Every game has the same method called join and the same parameters but each one does different things because these are different games. So when I iterate through my hashmap and find the specific value (arena) I want to be able to call the Capture the flag join method like this: