code: def test_merge():
      a = {"x": 1, "y": {"a": 1}}
      b = {"x": 2, "z": 3, "y": {"b": 2}}
  
      expected = {"x": 2, "y": {"a": 1, "b": 2}, "z": 3}
  
      c = merge(a, b)
      assert c == expected
  
imports: from __future__ import annotations
  import os
  import site
  import stat
  import sys
  from collections import OrderedDict
  from contextlib import contextmanager
  import pytest
  import yaml
  import dask.config
  from dask.config import _get_paths, canonical_name, collect, collect_env, collect_yaml, config, deserialize, ensure_file, expand_environment_variables, get, merge, pop, refresh, rename, serialize, update, update_defaults
  from dask.utils import tmpfile
label_desc: Use image node_id 7 for calling a global function with example usage: test_merge() without return types