ap containing
AP interfaces and classes (those not part of the Java
distribution).
Note that the official AP Java subset is not in a package
ap, but this documentation shows it in a package
ap to make it clear that these classes
and interfaces are part of the AP Computer Science
Java subset and not part of standard Java.
Interfaces and classes
that are in the package ap, and not in a sub-package,
are only used in the AB course.