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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def addClass(self, cn):
        '''Add the specific class names to the class set and return ``self``.
        '''
        if cn:
            if isinstance(cn, (tuple, list, set, frozenset)):
                add = self.addClass
                for c in cn:
                    add(c)
            else:
                classes = self._classes
                if classes is None:
                    self._extra['classes'] = classes = set()
                add = classes.add
                for cn in cn.split():
                    add(slugify(cn))
        return self