Draft - do not review

[scotthart]

This change is 

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 86.43678% with 59 lines in your changes missing coverage. Please review.

Project coverage is 92.92%. Comparing base (2d8e23a) to head (39948f2). Report is 7 commits behind head on main.

Files with missing lines	Patch %	Lines
google/cloud/spanner/internal/connection_impl.cc	76.19%	10 Missing :warning:
google/cloud/spanner/internal/session_pool.cc	91.15%	10 Missing :warning:
...e/cloud/spanner/internal/spanner_auth_decorator.cc	0.00%	10 Missing :warning:
...loud/spanner/internal/spanner_logging_decorator.cc	0.00%	7 Missing :warning:
...gle/cloud/spanner/internal/spanner_tracing_stub.cc	0.00%	7 Missing :warning:
...oud/spanner/internal/spanner_metadata_decorator.cc	0.00%	6 Missing :warning:
google/cloud/spanner/internal/spanner_stub.cc	0.00%	5 Missing :warning:
...le/cloud/spanner/internal/transaction_impl_test.cc	95.69%	4 Missing :warning:

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #15228      +/-   ##
==========================================
- Coverage   92.95%   92.92%   -0.04%     
==========================================
  Files        2394     2394              
  Lines      215516   215391     -125     
==========================================
- Hits       200337   200151     -186     
- Misses      15179    15240      +61     

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

:rocket: New features to boost your workflow:

• :snowflake: Test Analytics: Detect flaky tests, report on failures, and find test suite problems.