the following program should print "false", as the classof a is an anonymous
class that was not declared as an enumeration type.

The proper implementation of isEnum should check both the ACC_ENUM bit on
the class AND that the direct supertype is java.lang.Enum.  Only when both
conditions are true should the method return true.

enum E {
    a {};
    public static void main(String[] args) {
        System.out.println(a.getClass().isEnum());
    }
}