User-defined function for handling retries

Hi!

In the durable function documentation there is a line about callbacks in retry policies:

https://docs.microsoft.com/en-us/azure/azure-functions/durable/durable-functions-error-handling?tabs=python

>Handle: A user-defined callback can be specified to determine whether a function should be retried.

Looking through the code and documentation I can't find any examples of how this works. Is this supported in python durable functions? If so, how?

从 issue 中链接的 Durable Functions 错误处理文档开始，并检查 Python 库是否支持 retry policy callback。完成的标准是确定 Python 是否支持用户定义的 retry callback，并通过一个具体示例记录其用法或限制。

由索引模型根据 Issue 内容生成。