code: def _test_example_prompt(self, tokenizer):
      random.seed(5)
      conv = get_prompt_template_example(self.special_tokens)
      expected = (
          self.special_tokens["system_turn_start"]
          + "System"
          + self.special_tokens["end_of_name"]
          + "{system message}"
          + self.special_tokens["end_of_turn"]
      )
      for turn in range(2):
          expected += (
              self.special_tokens["turn_start"]
              + "User"
              + self.special_tokens["end_of_name"]
              + f"{{turn {turn + 1} user message}}"
              + self.special_tokens["end_of_turn"]
          )
          expected += (
              self.special_tokens["turn_start"]
              + "Assistant"
              + self.special_tokens["end_of_name"]
          )
          expected += (
              self.special_tokens["label_start"]
              + f"{{turn {turn + 1} assistant label}}"
              + self.special_tokens["end_of_name"]
          )
          expected += (
              f"{{turn {turn + 1} assistant message}}"
              + self.special_tokens["end_of_turn"]
          )
      expected += self.special_tokens["turn_start"]
      assert conv == expected
  
imports: import json
  import os
  import random
  from functools import partial
  import pytest
  from nemo.collections.nlp.data.language_modeling.megatron.gpt_sft_chat_dataset import GPTSFTChatDataset, get_prompt_template_example
  from nemo.collections.nlp.modules.common.tokenizer_utils import get_nmt_tokenizer
label_desc: Use image node_id 8 for calling the TestGPTSFTChatDataset obj's underlying member method code with example usage: obj._test_example_prompt(tokenizer) without return types