code: def merge_path_config(configs, config_dir_override):
      
      config_dir = None
      log_dir = None
      data_dir = None
      key_dir = None
      policy_dir = None
  
      for config in reversed(configs):
          if config.config_dir is not None:
              config_dir = config.config_dir
          if config.log_dir is not None:
              log_dir = config.log_dir
          if config.data_dir is not None:
              data_dir = config.data_dir
          if config.key_dir is not None:
              key_dir = config.key_dir
          if config.policy_dir is not None:
              policy_dir = config.policy_dir
  
      if config_dir_override is not None:
          config_dir = config_dir_override
  
      return PathConfig(
          config_dir=config_dir,
          log_dir=log_dir,
          data_dir=data_dir,
          key_dir=key_dir,
          policy_dir=policy_dir)
docs: Given a list of PathConfig objects, merges them into a single PathConfig,
      giving priority in the order of the configs (first has highest priority).