What problem do you want to solve?

I use a custom sampler that allows overriding of sampling decisions based on attributes, but I can't use that sampler in the sqlalchemy instrumentor because there is no way to pass attributes.

Describe the solution you'd like

Add an optional 0-argument callable as a kwarg to the instrumentor which lets you inject attributes at sample start time. #2733

Describe alternatives you've considered

No response

Additional Context

No response

Would you like to implement a fix?

Yes