<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def as_dict(self):
 """ Json-serializable dict representation of CompleteDos. """

        d = {"@module": self.__class__.__module__,
             "@class": self.__class__.__name__, "efermi": self.efermi,
             "structure": self.structure.as_dict(),
             "energies": list(self.energies),
             "densities": {str(spin): list(dens)
                           for spin, dens in self.densities.items()},
             "pdos": []}
        if len(self.pdos) > 0:
            for at in self.structure:
                dd = {}
                for orb, pdos in self.pdos[at].items():
                    dd[str(orb)] = {"densities": {str(int(spin)): list(dens)
                                                  for spin,
                                                      dens in pdos.items()}}
                d["pdos"].append(dd)
            d["atom_dos"] = {str(at): dos.as_dict() for at,
                                                        dos in self.get_element_dos().items()}
            d["spd_dos"] = {str(orb): dos.as_dict() for orb,
                                                        dos in self.get_spd_dos().items()}
        return d