Fixed
- senderEmail is now nullable (?string) on GetTransacBlockedContactsResponseContactsItem; the API returns null for some blocked or unsubscribed contacts (#137)
- campaignId is now nullable (?int) on both UserUnsubscription item classes; form based unsubscriptions return null (#136)
- Guzzle timeout support now works: interface_exists replaces class_exists for GuzzleHttp\ClientInterface, so the timeout option is honored (#133)
Backward compatible patch release. No breaking changes.