PhoneBook - [Sorting by Name and Sorting by Phone Number] This extends the PhoneBook class by adding sorting by phone number and a binary search.
Registrar - [Sorting by ID] The Registrar class is responsible to support the enrollment of students. This class maintains the student body as a collection of Student objects. It supports the ability to find and remove students, switch students to another program, and get the number of students enrolled in a specific program.
CDLibrary - [Not Yet Implemented] This class manages a collection of CDs that are stored in alphabetical order. It supports searching the library for CDs based on the title.