class_docstr: Extending hook so that a mockmongo collection object can be passed in
  to get_collection()
code: def get_collection(self, mock_collection, mongo_db=None):
      return mock_collection
  
imports: from __future__ import annotations
  import importlib
  from typing import TYPE_CHECKING
  import pymongo
  import pytest
  from airflow.models import Connection
  from airflow.providers.mongo.hooks.mongo import MongoHook
  from airflow.utils import db
label_desc: Use image node_id 2 for calling the MongoHookTest obj's underlying member method code with example usage: obj.get_collection(mock_collection, mongo_db) and returns: mock_collection