code: def get_time_str(time_in_milliseconds):
      dt_time = dt.utcfromtimestamp(time_in_milliseconds / 1000.0)
      return dt_time.strftime("%Y-%m-%d %H:%M:%S,000")
  
imports: from __future__ import annotations
  import contextlib
  import logging
  import time
  from datetime import datetime, timedelta
  from unittest import mock
  from unittest.mock import ANY, Mock, call
  import boto3
  import moto
  import pytest
  from watchtower import CloudWatchLogHandler
  from airflow.models import DAG, DagRun, TaskInstance
  from airflow.operators.empty import EmptyOperator
  from airflow.providers.amazon.aws.hooks.logs import AwsLogsHook
  from airflow.providers.amazon.aws.log.cloudwatch_task_handler import CloudwatchTaskHandler
  from airflow.providers.amazon.aws.utils import datetime_to_epoch_utc_ms
  from airflow.utils.session import create_session
  from airflow.utils.state import State
  from airflow.utils.timezone import datetime
  from tests.test_utils.config import conf_vars
label_desc: Use image node_id 1 for calling a global function with example usage: get_time_str(time_in_milliseconds) and returns: dt_time