covariant interfaces in java

interface Condiment {}
interface Ketchup extends ISuper {}

// This is a covariant interface
interface Kitchen<T extends Condiment> {
    public void squirtCondiment(T covariant);
}

// This implements the Kitchen interface even though the implementation refers specifically to Ketchup in the type signature
class KetchupKitchen implements Kitchen<Ketchup> {
    public void squirtCondiment(Ketchup covariant) {

    }
}