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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 as_dict(self):
 """ Json-serializable dict representation of PhononDos. """

        return {"@module": self.__class__.__module__,
                "@class": self.__class__.__name__,
                "frequencies": list(self.frequencies),
                "densities": list(self.densities)}