java Enum definition

Class Enum<E extends Enum<E>>

public class StatusCode extends Enum<StatusCode>


Now if you check the constraints, we've got Enum<StatusCode>

public interface IBuilder<TMessage, TBuilder>
    where TMessage : IMessage<TMessage, TBuilder>
    where TBuilder : IBuilder<TMessage, TBuilder>

  public interface IMessage<TMessage, TBuilder>
    where TMessage : IMessage<TMessage, TBuilder>
    where TBuilder : IBuilder<TMessage, TBuilder>

enum Season { WINTER, SPRING, SUMMER, FALL }

final class Season extends ...

Season extends ... implements Comparable<Season>

Season extends Enum<Season>
Enum<Season> implements Comparable<Season>

E extends Enum<E>

public abstract class Node<T extends Node<T>>
{
    public void addNeighbor(T);

    public void addNeighbors(Collection<? extends T> nodes);

    public Collection<T> getNeighbor();
}

public class City extends Node<City>
{
    public void addNeighbor(City){...}

    public void addNeighbors(Collection<? extends City> nodes){...}

    public Collection<City> getNeighbor(){...}
}