class Course:

def $\_\_$init$\_\_($self$,$ course$\_$id$,$ craft$\_$type, schedule, time, cost, teacher, vacancy, students$=[])$:

self.course$\_$id $=$ course$\_$id

self.craft$\_$type $=$ craft$\_$type

self.schedule $=$ schedule

self.time $=$ time

self.cost $=$ cost

self.teacher $=$ teacher

self.vacancy$=$ vacancy

self.students $=$ students

def add$\_$student$($self$,$ student, amount$)$:

if len$($self$.$students$)<$ self.vacancy:

self.students.append$(($student$,$ amount$))$

self.vacancy $-=1$

return True

return False

How can I write unit tests for each function of this code?