class School():
    def __init__(self, name):
        self.name = name
        self._roster = {}
        
    def roster(self):
        return self._roster
    
    def add_student(self, name, grade):
        if grade not in self._roster.keys():
            self._roster[grade] = []
        self._roster[grade].append(name)
        
    def grade(self, grade):
        return self._roster[grade]
    
    def sort_roster(self):
        return { key: sorted(value) for key, value in self._roster.items() }
628d82962f0c664b23a508194289997f4b48a613
class School:

    def __init__(self, name):
        self.name = name
        self._roster = {}
    <mask token>

    def add_student(self, name, grade):
        if grade not in self._roster.keys():
            self._roster[grade] = []
        self._roster[grade].append(name)
    <mask token>
    <mask token>

class School:

    def __init__(self, name):
        self.name = name
        self._roster = {}
    <mask token>

    def add_student(self, name, grade):
        if grade not in self._roster.keys():
            self._roster[grade] = []
        self._roster[grade].append(name)
    <mask token>

    def sort_roster(self):
        return {key: sorted(value) for key, value in self._roster.items()}

class School:

    def __init__(self, name):
        self.name = name
        self._roster = {}
    <mask token>

    def add_student(self, name, grade):
        if grade not in self._roster.keys():
            self._roster[grade] = []
        self._roster[grade].append(name)

    def grade(self, grade):
        return self._roster[grade]

    def sort_roster(self):
        return {key: sorted(value) for key, value in self._roster.items()}

class School:

    def __init__(self, name):
        self.name = name
        self._roster = {}

    def roster(self):
        return self._roster

    def add_student(self, name, grade):
        if grade not in self._roster.keys():
            self._roster[grade] = []
        self._roster[grade].append(name)

    def grade(self, grade):
        return self._roster[grade]

    def sort_roster(self):
        return {key: sorted(value) for key, value in self._roster.items()}

class School():
    def __init__(self, name):
        self.name = name
        self._roster = {}
        
    def roster(self):
        return self._roster
    
    def add_student(self, name, grade):
        if grade not in self._roster.keys():
            self._roster[grade] = []
        self._roster[grade].append(name)
        
    def grade(self, grade):
        return self._roster[grade]
    
    def sort_roster(self):
        return { key: sorted(value) for key, value in self._roster.items() }