code: def test_json_merge(client):
      # Test with root path $
      assert client.json().set(
          "person_data",
          "$",
          {"person1": {"personal_data": {"name": "John"}}},
      )
      assert client.json().merge(
          "person_data",
          "$",
          {"person1": {"personal_data": {"hobbies": "reading"}}},
      )
      assert client.json().get("person_data") == {
          "person1": {
              "personal_data": {"name": "John", "hobbies": "reading"}
          }
      }
  
      # Test with root path path $.person1.personal_data
      assert client.json().merge(
          "person_data",
          "$.person1.personal_data",
          {"country": "Israel"},
      )
      assert client.json().get("person_data") == {
          "person1": {
              "personal_data": {
                  "name": "John",
                  "hobbies": "reading",
                  "country": "Israel",
              }
          }
      }
  
      # Test with null value to delete a value
      assert client.json().merge(
          "person_data", "$.person1.personal_data", {"name": None}
      )
      assert client.json().get("person_data") == {
          "person1": {
              "personal_data": {
                  "country": "Israel",
                  "hobbies": "reading",
              }
          }
      }
  
imports: import pytest
  import redis
  from redis import Redis, exceptions
  from redis.commands.json.decoders import decode_list, unstring
  from redis.commands.json.path import Path
  from .conftest import _get_client, assert_resp_response, skip_ifmodversion_lt
label_desc: Use image node_id 6 for calling a global function with example usage: test_json_merge(client) without return types