code: def test_new_metrics_endpoint_should_not_display_deprecation_warning(
      self,
  ):
      response = self.fetch("/_stcore/metrics")
      self.assertNotIn("link", response.headers)
      self.assertNotIn("deprecation", response.headers)
  
file_path: streamlit/lib/tests/streamlit/web/server/stats_handler_test.py
imports: from unittest.mock import MagicMock
  import tornado.testing
  import tornado.web
  from google.protobuf.json_format import MessageToDict
  from tornado.httputil import HTTPHeaders
  from streamlit.proto.openmetrics_data_model_pb2 import MetricSet
  from streamlit.runtime.stats import CacheStat
  from streamlit.web.server.server import METRIC_ENDPOINT
  from streamlit.web.server.stats_request_handler import StatsRequestHandler
label_desc: Use image node_id 5 for calling the StatsHandlerTest obj's underlying member method code with example usage: obj.test_new_metrics_endpoint_should_not_display_deprecation_warning() without return types