fix doc

docs/sphinx_doc/en/source/tutorial/208-distribute.md

@@ -446,7 +446,7 @@ as_server start --host localhost --port 12345 --model-config-path model_config_p
 
 ##### `result_pool`
 
-The `ResultPool` implementation is located in `src/agentscope/server/async_result_pool.py` and is used for managing the execution results of asynchronous methods. There are currently two implementations: `local` and `redis`. The `local` implementation is based on Python's dictionary type (`dict`), whereas the `redis` implementation is based on Redis. Both implementations include automatic deletion mechanisms to prevent results from consuming too much memory. The `local` implementation allows for timeout-based deletion (`max_expire`) or deletion when a certain number of items is exceeded (`max_len`), while the `redis` implementation only supports timeout-based deletion (`max_expire_time`).
+The `ResultPool` implementation is located in `src/agentscope/server/async_result_pool.py` and is used for managing the execution results of asynchronous methods. There are currently two implementations: `local` and `redis`. The `local` implementation is based on Python's dictionary type (`dict`), whereas the `redis` implementation is based on Redis. Both implementations include automatic deletion mechanisms to prevent results from consuming too much memory. The `local` implementation allows for timeout-based deletion (`max_expire_time`) or deletion when a certain number of items is exceeded (`max_len`), while the `redis` implementation only supports timeout-based deletion (`max_expire_time`).
 During the startup of `AgentServerLauncher`, you can specify which implementation to use by passing in the `pool_type` parameter, with the default being `local`.
 If `redis` is specified, you must also provide the `redis_url`. Below are examples of code and command-line usage.