code: def make_modular(self, rebuild=False):
          
          if rebuild is True:
              supercell_333 = create_supercell(self.system)
          else:
              supercell_333 = None
          dis = discrete_molecules(self.system, rebuild=supercell_333)
          self.no_of_discrete_molecules = len(dis)
          self.molecules = {}
          for i in range(len(dis)):
              self.molecules[i] = Molecule(dis[i], self.system_id, i)
docs: Find and return all :class:`Molecule` s in :class:`MolecularSystem`.
  
          This function populates :attr:`MolecularSystem.molecules` with
          :class:`Molecule` s.
  
          Parameters
          ----------
          rebuild : :class:`bool`
              If True, run first the :func:`rebuild_system()`. (default=False)
  
          Returns
          -------
          None : :class:`NoneType`