docs: def get_slice_from_res_id(self, start, end):
          """Returns a new `Polypeptide` containing the `Residues` in start/end range.
  
          Parameters
          ----------
          start : str
              string representing start residue id (PDB numbering)
          end : str
              string representing end residue id (PDB numbering)
  
          Returns
          -------
          slice_polymer : Polymer
              Polymer containing the residue range specified by start-end
          """
  
          id_dict = {str(m.id): m for m in self._monomers}
          slice_polymer = Polypeptide(
              [id_dict[str(x)] for x in range(int(start), int(end) + 1)], self.id)
          return slice_polymer