code: def test_first():
      assert (
          func.first([0, [], (), None, False, {}, 0.0, "1", 0]) == "1"
      )
      assert func.first([]) is None
      assert func.first([0]) is None
  
file_path: catboost/library/python/func/ut/test_func.py
imports: import pytest
  import multiprocessing
  import random
  import threading
  import time
  import library.python.func
label_desc: Use image node_id 4 for calling a global function with example usage: test_first() without return types