$```$

from Gradebook import Gradebook

class CourseGradebook$($Gradebook$)$:

def $\_\_$init$\_\_($self$)$:

self.grades $=\{\}$

# Type any code needed here

# Return a dict that maps students to scores

# An entry exists for a student only if one had been assigned by set$\_$score

def get$\_$assignment$\_$scores$($self$,$ assignment$\_$name$)$:

result $=\{\}$

# Type your code here. $($remove placeholder line below$)$

return result

def get$\_$score$($self$,$ assignment$\_$name, studentID$)$:

# Type your code here. $($remove placeholder line below$)$

return None

def get$\_$sorted$\_$assignment$\_$names$($self$)$:

result $=[]$

# Type your code here. $($remove placeholder line below$)$

return result

# get$\_$sorted$\_$student$\_$ids$()$ returns a list with all distinct student ID$,$

# sorted in ascending order.

def get$\_$sorted$\_$student$\_$IDs$($self$)$:

result $=[]$

# Type your code here. $($remove placeholder line below$)$

return result

# get$\_$student$\_$scores$()$ gets all scores that exist in the gradebook for the

# student whose ID matches the method argument, and returns a dict that maps

# each assignment name to the student's score for that assignment.

def get$\_$student$\_$scores$($self$,$ studentID$)$:

result $=\{\}$

# Type your code here. $($remove placeholder line below$)$

return result

def set$\_$score$($self$,$ assignment$\_$name, studentID, score$)$:

# Type your code here.

pass

$```$