This was copied from `tests/generic/mongocollection-aggregatecursor_error-003.phpt` and `tests/generic/mongocollection-aggregatecursor_error-004.phpt` in https://github.com/jmikola/mongo-php-driver/commit/c25efd3b29f70727e7f49715cb4a1d180d2da057 from #643.

@derickr: Does this test still qualify as an error test? It's my understanding that the server will allow `batchSize` of `0` (it just can't be negative or a non-number), so this should probably be a regular test. Likely named `mongocollection-aggregatecursor-006.phpt` so not to conflict with my existing tests in #643.