Error:
(venv) (base) ➜ mypy .
test.py:3: error: Module has no attribute "MAX_BSON_SIZE"
Found 1 error in 1 file (checked 1 source file)
code of pymongo:

https://github.com/mongodb/mongo-python-driver/blob/e6b65860f59b432487fcdb385fde663345ce2917/pymongo/common.py#L56
Minimal working example:
import pymongo
print(pymongo.common.MAX_BSON_SIZE)
Requirements:
pip install pymongo mypy mongo-types