What's Changed
Features:
* For failed transaction, return the underlying item in `cancellation_reasons[...].raw_item` (1226). This only applies when passing `return_values=ALL_OLD`.
Fixes:
* Fixing (1242) regression to the `extra_headers` feature. These headers are intended for proxies that strip them, so they should be excluded from the AWS signature.
**Full Changelog**: https://github.com/pynamodb/PynamoDB/compare/6.0.0...6.0.1