new_contents: class Gridded:
  
      _grid_obj_classes = []
      _grids_loaded = False
  
      @classmethod
      def _load_grid_objs(cls):
          from pkg_resources import working_set
          for ep in working_set.iter_entry_points('gridded.grid_objects'):
              cls._grid_obj_classes.append(ep.load())
  
      @classmethod
      def load(cls, nc, *args, **kwargs):
          for go in self._grid_obj_classes:
              if hasattr(go, 'is_mine') and go.is_mine(nc):
                  return go(nc, *args, **kwargs)
  
  
subject: Add Gridded loader module (to be moved)