chore(main): release 3.19.1

Author: release-please[bot]

CHANGELOG.md

@@ -4,6 +4,13 @@
 
 [1]: https://pypi.org/project/google-cloud-spanner/#history
 
+## [3.19.1](https://github.com/googleapis/python-spanner/compare/v3.19.0...v3.19.1) (2022-08-25)
+
+
+### Bug Fixes
+
+* if JsonObject serialized to None then return `null_value` instead of `string_value` ([#771](https://github.com/googleapis/python-spanner/issues/771)) ([82170b5](https://github.com/googleapis/python-spanner/commit/82170b521f0da1ba5aaf064ba9ee50c74fe21a86))
+
 ## [3.19.0](https://github.com/googleapis/python-spanner/compare/v3.18.0...v3.19.0) (2022-08-17)
 
 

setup.py

@@ -22,7 +22,7 @@
 
 name = "google-cloud-spanner"
 description = "Cloud Spanner API client library"
-version = "3.19.0"
+version = "3.19.1"
 # Should be one of:
 # 'Development Status :: 3 - Alpha'
 # 'Development Status :: 4 - Beta'