ClassExample.swift

// Our Original class
class Example {
    
    // Original function
    class func start() {
        print("Start")
    }
}

// Subclassing
class ExampleSubclass: Example {
    
    // Overriding the function
    override class func start() {
        super.start()
        print("Overridden Start")
    }
}

Example.start() // This will print "Start" in the console.
ExampleSubclass.start() // This will print "Start" and "Overridden Start" in the console.