User subclasses uses functions and variables from its superclass

src/main/java/softeng/g4/user/Admin.java

src/main/java/softeng/g4/user/Student.java

src/main/java/softeng/g4/user/TeachingAssistant.java

src/main/java/softeng/g4/user/User.java

src/main/java/softeng/g4/user/UserStudent.java

src/main/java/softeng/g4/userlist.txt