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?

Start with the Durable Functions error-handling documentation linked in the issue and inspect the Python library for retry-policy callback support. Done means establishing whether user-defined retry callbacks are supported in Python and documenting the usage or limitation with a concrete example.

Written by the indexing model from the issue text.