class Chocolate():
    def __init__(self):
        self._cacao_content = 0

    def sweet(self):
        self._cacao_content = 30
        return self._cacao_content

    def semisweet(self):
        self._cacao_content = 50
        return self._cacao_content

    def bittersweet(self):
        self._cacao_content = 70
        return self._cacao_content

    def bitter(self):
        self._cacao_content = 99
        return self._cacao_content

candy = Chocolate()