code: def register_field(cls, field):
      
      FieldRegistry.add_field(cls, field)
      
      signals.post_save.connect(handle_save_embeds, sender=cls,
              dispatch_uid='%s.%s.%s' % \
              (cls._meta.app_label, cls._meta.module_name, field.name))
docs: Handles registering the fields with the FieldRegistry and creating a 
      post-save signal for the model.