docstr: get/set timestamps with datetime objects
docstr_tok: ["get\/set","timestamps","with","datetime","objects"]
code: def test_datetime(self):
      """get/set timestamps with datetime objects"""
      msg_id = self.db.get_history()[-1]
      rec = self.db.get_record(msg_id)
      assert isinstance(rec["submitted"], datetime)
      self.db.update_record(msg_id, dict(completed=util.utcnow()))
      rec = self.db.get_record(msg_id)
      assert isinstance(rec["completed"], datetime)
  
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 13 for calling the TaskDBTest obj's underlying member method code with example usage: obj.test_datetime() without return types