docs: def _instance_parser(self, plugins):
          """
          internal method to parse instances of plugins.
  
          Determines if each class is a class instance or
          object instance and calls the appropiate handler
          method.
          """
          plugins = util.return_list(plugins)
          for instance in plugins:
              if inspect.isclass(instance):
                  self._handle_class_instance(instance)
              else:
                  self._handle_object_instance(instance)