code: def test_drop_matching(self):
      msg_ids = self.load_records(10)
      query = {"msg_id": {"$in": msg_ids}}
      self.db.drop_matching_records(query)
      recs = self.db.find_records(query)
      assert len(recs) == 0
  
imports: import logging
  import os
  import tempfile
  import time
  from datetime import datetime, timedelta
  from unittest import TestCase
  import pytest
  from jupyter_client.session import Session
  from ipyparallel import util
  from ipyparallel.controller.dictdb import DictDB
  from ipyparallel.controller.hub import init_record
  from ipyparallel.controller.sqlitedb import SQLiteDB
  from ipyparallel.util import utc
label_desc: Use image node_id 14 for calling the TaskDBTest obj's underlying member method code with example usage: obj.test_drop_matching() without return types