[illuminati1911]

Summary

• Include enableUspsCass in the JSON request only when its value is not None.
• Preserve explicitly supplied True and False values.
• Replace the URL-only test with serialized-request regression coverage and add a changelog entry.

The existing condition is always true, including for the default None value, so an omitted option is sent as JSON null: https://github.com/googlemaps/google-maps-services-python/blob/d3b71ab1333cff0f900d2db6b39c1356341a5ea2/googlemaps/addressvalidation.py#L47-L75

This corrects unintended serialization; it does not claim that the API rejects null. The existing documentation and response handling are otherwise unchanged.

Verification

• Python 3.10: python -m pytest tests/test_addressvalidation.py — 1 passed, covering omitted, true, and false serialization cases.
• Python 3.10: python -m pytest — 105 passed.
• Reproduced the original null serialization before the fix and confirmed the correction afterward with locally intercepted requests and live sockets blocked.
• Also exercised the committed fix over real loopback HTTP for omitted, explicit None, True, and False inputs. Confirmed successful results and preservation of other address fields. No Google Maps requests or real credentials were used.
• nox --download-python never -s docs --force-python 3.10 — passed. Visually inspected generated Sphinx documentation and the rendered changelog in Chromium.
• The prescribed Python 3.7 docs build remains unverified because Python 3.7 is unavailable on this machine. The Python 3.10 build is supplemental.
• Pytest ran directly with the repository's test dependencies to avoid the Nox follow-on Codecov upload.