code: def setup_method(self, method):
      self._token_cost_estimator = OpenAITokenCostEstimator()
      self._mock_metric_service = MetricService(
          RemoteService(), Authentication(api_key="test")
      )
      gpt2_tokenizer = GPT2TokenizerFast.from_pretrained("gpt2")
      tokenization_request_result = TokenizationRequestResult(
          success=True,
          cached=False,
          text=TestOpenAITokenCostEstimator.TEST_PROMPT,
          tokens=[
              TokenizationToken(value)
              for value in gpt2_tokenizer.tokenize(
                  TestOpenAITokenCostEstimator.TEST_PROMPT
              )
          ],
      )
      self._mock_metric_service.tokenize = MagicMock(
          return_value=tokenization_request_result
      )
  
file_path: H2O/h2o_hf/helm/src/helm/benchmark/metrics/tokens/test_openai_token_cost_estimator.py
imports: from unittest.mock import MagicMock
  from transformers import GPT2TokenizerFast
  from helm.benchmark.metrics.metric_service import MetricService
  from helm.common.authentication import Authentication
  from helm.common.request import Request
  from helm.common.tokenization_request import TokenizationRequestResult, TokenizationToken
  from helm.proxy.services.remote_service import RemoteService
  from .openai_token_cost_estimator import OpenAITokenCostEstimator
label_desc: Use image node_id 1 for calling the TestOpenAITokenCostEstimator obj's underlying member method code with example usage: obj.setup_method(method) without return types