Complete the Course class by implementing the dropStudent$()$ method, which removes a student $($by last name$)$ from the course roster. If the student is not found in the course roster, no student should be dropped. Assume all students have distinct last names.

Given classes:

Class Course represents a course, which contains an ArrayList of Student objects as a course roster. $($Type your code in here.$)$

Class Student represents a classroom student, which has three private fields: first name, last name, and GPA. $($Hint: getLast$()$ returns the last name field.$)$

Ex: If the following students and their GPA values are added to a course:

Henry Nguyen with $3\mathrm{.}5$ GPA

Brenda Stern with $2\mathrm{.}0$ GPA

Lynda Robison with $3\mathrm{.}2$ GPA

Sonya King with $3\mathrm{.}9$ GPA

then dropStudent$($last$),$ where last is "Stern", removes a student and the program output is:

Course size: $4$ students Course size after drop: $3$ students