code: def _sample_long_func(a: int, b: str):
      time.sleep(2.7)
      return dict(a=a, b=b)
  
imports: import random
  import time
  import unittest
  from unittest.mock import MagicMock, patch
  import fakeredis
  from gokart.redis_lock import RedisClient, RedisParams, make_redis_key, make_redis_params, wrap_with_dump_lock, wrap_with_load_lock, wrap_with_remove_lock, wrap_with_run_lock
label_desc: Use image node_id 2 for calling a global function with example usage: _sample_long_func(a, b) and returns: dict