Unknown Reported by GitHub user @sibbiii in https://github.com/mongodb-labs/mongo-arrow/issues/163. We should add use their repro as a test and fix the bug.
collection = ...
obj_id = bson.ObjectId()
collection.insert_one(
{'_id': obj_id,
'id1': obj_id,
'obj': {'id2': obj_id}
})
print(pymongoarrow.api.find_arrow_all(collection, {}))
print(pymongoarrow.api.find_arrow_all(collection, {}).to_pandas())