code: def test_to_dict_default(self):
      component = OpenAIChatGenerator(api_key="test-api-key")
      data = component.to_dict()
      assert data == {
          "type": "haystack.components.generators.chat.openai.OpenAIChatGenerator",
          "init_parameters": {
              "model": "gpt-3.5-turbo",
              "organization": None,
              "streaming_callback": None,
              "api_base_url": None,
              "generation_kwargs": {},
          },
      }
  
imports: import os
  import pytest
  from openai import OpenAIError
  from haystack.components.generators.chat import OpenAIChatGenerator
  from haystack.components.generators.utils import default_streaming_callback
  from haystack.dataclasses import ChatMessage, StreamingChunk
label_desc: Use image node_id 4 for calling the TestOpenAIChatGenerator obj's underlying member method code with example usage: obj.test_to_dict_default() without return types