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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 swap(self):
 # type: () -> DictWrapper """Swap key and value /!\ Be carreful, if there are duplicate values, only one will survive /!\ Example: {2: 2, 3: 3} """

        return self.__class__((v, k) for k, v in self.items())