This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
All enum classes implicitly extend the Enum class. The Enum class signature is : Class Enum<E extends Enum<E>>. When you declare an enum class like "public enum TimeUnit", it implicitly becomes "public enum TimeUnit extends Enum<TimeUnit>". This is discribed here : The direct superclass of an enum type named E is Enum<E>.