code: def test_dict_merge():
      assert utils.dict_merge(dict(a=1), dict(b=2)) == dict(a=1, b=2)
      assert utils.dict_merge(dict(a=1), dict(a=2)) == dict(a=2)
      assert utils.dict_merge(None, dict(b=2)) == dict(b=2)
      assert utils.dict_merge(dict(a=1), None) == dict(a=1)
  
file_path: dtale/tests/dtale/test_utils.py
imports: from collections import namedtuple
  import mock
  import numpy
  import pandas
  import pytest
  from six import PY3
  import dtale.utils
  from tests import ExitStack
label_desc: Use image node_id 6 for calling a global function with example usage: test_dict_merge() without return types