code: def add_cohp(self, label, cohp):
          
          energies = cohp.energies - cohp.efermi if self.zero_at_efermi \
              else cohp.energies
          populations = cohp.get_cohp()
          int_populations = cohp.get_icohp()
          self._cohps[label] = {"energies": energies, "COHP": populations,
                                "ICOHP": int_populations, "efermi": cohp.efermi}
docs: Adds a COHP for plotting.
  
          Args:
              label: Label for the COHP. Must be unique.
  
              cohp: COHP object.