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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 Dos. """

        return {"@module": self.__class__.__module__,
                "@class": self.__class__.__name__, "efermi": self.efermi,
                "energies": list(self.energies),
                "densities": {str(spin): list(dens)
                              for spin, dens in self.densities.items()}}