Declaring a class that works with two constrained generic types

Now, it is time to code another protocol that will be used as a constraint later when we define another class that takes advantage of generics with two constrained generic types. The following lines show the code for the DeeJayProtocol protocol. The public modifier followed by the protocol keyword and the protocol name, DeeJayProtocol, composes the protocol declaration, as follows:

public protocol DeeJayProtocol {
    var name: String { get }
    
    init(name: String)
    
    func playMusicToDance()
    func playMusicToSing()
}

The protocol declares a name String read-only stored property and two method requirements: playMusicToDance and playMusicToSing. As you learned in the previous chapter, the protocol includes only the method declaration because the classes that conform to the DeejayProtocol protocol will be responsible for providing the implementation of the name stored property and the other two methods.

In addition...