code: def validate_plugin(self, plugin_class, experimental=False):
          
          valid_subclasses = [IndependentPlugin] + self.valid_subclasses
          if experimental:
              valid_subclasses += [ExperimentalPlugin]
          return any(issubclass(plugin_class, class_) for
                     class_ in valid_subclasses)
docs: Verifies that the plugin_class should execute under this policy