code: def transfer_options(cls, obj, new_obj, backend=None):
          
          backend = cls.current_backend if backend is None else backend
          type_name = type(new_obj).__name__
          group = type_name if obj.group == type(obj).__name__ else obj.group
          spec = '.'.join([s for s in (type_name, group, obj.label) if s])
          options = []
          for group in Options._option_groups:
              opts = cls.lookup_options(backend, obj, group)
              if opts and opts.kwargs: options.append(Options(group, **opts.kwargs))
          if options:
              StoreOptions.set_options(new_obj, {spec: options}, backend)
docs: Transfers options for all backends from one object to another.
          Drops any options defined in the supplied drop list.