code: def test_initialize_with_invalid_url(self, mock_check_valid_model):
      with pytest.raises(ValueError):
          HuggingFaceTGIChatGenerator(
              model="NousResearch/Llama-2-7b-chat-hf", url="invalid_url"
          )
  
imports: from unittest.mock import patch, MagicMock, Mock
  import pytest
  from huggingface_hub.inference._text_generation import TextGenerationStreamResponse, Token, StreamDetails, FinishReason
  from huggingface_hub.utils import RepositoryNotFoundError
  from haystack.components.generators.chat import HuggingFaceTGIChatGenerator
  from haystack.dataclasses import StreamingChunk, ChatMessage
label_desc: Use image node_id 8 for calling the TestHuggingFaceTGIChatGenerator obj's underlying member method code with example usage: obj.test_initialize_with_invalid_url(mock_check_valid_model) without return types