chore(x-goog-request-id): commit testing scaffold

[odeke-em]

This change commits the scaffolding for which testing will be used. This is a carve out of PRs #1264 and #1364, meant to make those changes lighter and much easier to review then merge.

Updates #1261

[odeke-em]

@rahul2393 kindly help me re-run the bots for this PR. Thank you

[odeke-em]

@rahul2393 kindly help me with another bot run, I've ensured all tests are passing locally.

[olavloite]

LGTM (with one tiny nit)

There is one test failure, but I don't really see how that could be related to this change:

=================================== FAILURES ===================================
_________________ TestDbApi.test_execute_batch_dml_abort_retry _________________

self = 
dbapi_database = 

    def test_execute_batch_dml_abort_retry(self, dbapi_database):
        """Test that when any execute batch dml failed with Abort exception,
        then the retry succeeds with transaction having insert as well as query
        type of statements along with batch dml statements."""
    
        method_count_interceptor = dbapi_database._method_count_interceptor
        method_count_interceptor.reset()
        # called 3 times
        self._insert_row(1)
        # called 3 times
        self._cursor.execute("SELECT * FROM contacts")
        self._cursor.fetchall()
        self._cursor.execute("start batch dml")
        self._insert_row(2)
        self._insert_row(3)
        dbapi_database._method_abort_interceptor.set_method_to_abort(
            EXECUTE_BATCH_DML_METHOD, self._conn, 2
        )
        # called 3 times
        self._cursor.execute("run batch")
        dbapi_database._method_abort_interceptor.reset()
        self._conn.commit()
        assert method_count_interceptor._counts[COMMIT_METHOD] == 1
        assert method_count_interceptor._counts[EXECUTE_BATCH_DML_METHOD] == 3
>       assert method_count_interceptor._counts[EXECUTE_STREAMING_SQL_METHOD] == 6
E       assert 8 == 6

(And if it is related to this change, then I expect it only to be related to test code, and not to affect any production code)

[olavloite]

nit: do we need both this method and the instance method above? If so, could we at least put the main bit of logic into one method?

[odeke-em]

Thanks for catching that, turns out you had already committed that code to main. I've removed it.

[odeke-em]

yeah that test failure is bizarre and the code I committed doesn't really touch production code and we already tested AtomicCounter.increment() and .reset() so I can't see a way either that it could work. Must be a flake. Kindly please help me re-run the bots @olavloite and thank you very much for the code review and approval!

[odeke-em]

@rahul2393 @olavloite @harshachinta kindly help me run the bots.