Describe the bug

When accessing item.subscription_item, I expect a None value but instead I get an Exception.

To Reproduce

stripe_invoice = stripe_repo.retrieve_stripe_invoice(existing_stripe_subscription.latest_invoice)
for item in stripe_invoice.lines.data:
     if item.subscription_item: # this throws an error if the item is not a subscription_item
        pass

Expected behavior

The expectation is that defaults to None if not a subscription_item.

(variable) subscription_item: ExpandableField[SubscriptionItem] | None
The subscription item that generated this line item. Left empty if the line item is not an explicit result of a subscription.

Code snippets

OS

macOS

Language version

Python 3.12.8

Library version

stripe 11.5.0

API version

2025-01-27.acacia

Additional context

No response