code: def test_custom_metrics_info(metric_mock):
      # Make sure .info public method works.
      histogram = Histogram(
          "hist",
          description="hist",
          boundaries=[1.0, 2.0],
          tag_keys=("a", "b"),
      )
      assert histogram.info["name"] == "hist"
      assert histogram.info["description"] == "hist"
      assert histogram.info["boundaries"] == [1.0, 2.0]
      assert histogram.info["tag_keys"] == ("a", "b")
      assert histogram.info["default_tags"] == {}
      histogram.set_default_tags({"a": "a"})
      assert histogram.info["default_tags"] == {"a": "a"}
  
imports: import signal
  import json
  import os
  import pathlib
  import sys
  import requests
  from pprint import pformat
  from unittest.mock import MagicMock
  import numpy
  import pytest
  import ray
  from ray.util.state import list_nodes
  from ray._private.metrics_agent import PrometheusServiceDiscoveryWriter
  from ray._private.ray_constants import PROMETHEUS_SERVICE_DISCOVERY_FILE
  from ray._private.test_utils import SignalActor, fetch_prometheus, fetch_prometheus_metrics, get_log_batch, wait_for_condition, raw_metrics
  from ray.autoscaler._private.constants import AUTOSCALER_METRIC_PORT
  from ray.dashboard.consts import DASHBOARD_METRIC_PORT
  from ray.util.metrics import Counter, Gauge, Histogram
label_desc: Use image node_id 10 for calling a global function with example usage: test_custom_metrics_info(metric_mock) without return types