docs: def relabel_atoms(self, start=1):
          """Relabels all Atoms in numerical order, offset by the start parameter.
  
          Parameters
          ----------
          start : int, optional
              Defines an offset for the labelling.
          """
          counter = start
          for atom in self.get_atoms(ligands=True):
              atom.id = counter
              counter += 1
          return