Static Fields
If there are constants associated with or useful for an interface,
those can be attached to the interface declaration as public static final
fields.
The declaration of these looks the same as declaring a normal field in a class.
The public static final
are implied.
interface Biped {
// This does the same as
// "public static final int NUMBER_OF_FEET = 2"
// in a normal class.
int NUMBER_OF_FEET = 2;
void walk();
}