code: def class_dict_to_topo_config(mcs, class_dict):
      
      topo_config = {}
  
      # add defaults
      topo_config.update(mcs.DEFAULT_TOPOLOGY_CONFIG)
  
      for name, custom_config in class_dict.items():
        if name == 'config' and isinstance(custom_config, dict):
          sanitized_dict = mcs._sanitize_config(custom_config)
          topo_config.update(sanitized_dict)
  
      return topo_config
docs: Takes a class `__dict__` and returns a map containing topology-wide
      configuration.
  
      The returned dictionary is a sanitized `dict` of type `<str ->
      (str|object)>`.
  
      This classmethod firsts insert default topology configuration and then
      overrides it with a given topology-wide configuration. Note that this
      configuration will be overriden by a component-specific configuration at
      runtime.