* Add mock code first
* In the initial progress.
* Fix the number error
* In progress.
* in more pgoress.
* in progress.
* lint.
* Prototype done.
* Fix compilation bug.
* Now it is working with reference counting.
* Remove template.
* lint.
* Fixed issues.
* Fix reference count test.
* Reference count test passes now.
* Fixed the test array problem
* Addressed code review.
* lint.
* Addressed half of code review.
* Fix tests.
* Addressed the most critical issue.
* Make subscriber thread-safe.
* Revert "Make subscriber thread-safe."
This reverts commit 9a6a52197cfa8463ab60dfaae9530ad3c0ed8790.
* Fixed test failures. The only failure now is the asan failure.
* Reset test suites and see if it fixes the issue.
* Fix a flaky test
* Addressed code review.
