docstr: Generate "route", "application" information from metrics.
  Args:
      metrics: list of metrics, each item is a dictionary generated from
          get_metric_dictionaries func.
  Return: return a Tuple[dictionary, dictionary]
      First dictionary: key is deployment name, value is a set
      including all routes. string is to indicate the applicationn name.
      Second dictionary: key is the deployment name, value is application name.
code: def _generate_metrics_summary(self, metrics):
      """Generate "route", "application" information from metrics.
      Args:
          metrics: list of metrics, each item is a dictionary generated from
              get_metric_dictionaries func.
      Return: return a Tuple[dictionary, dictionary]
          First dictionary: key is deployment name, value is a set
          including all routes. string is to indicate the applicationn name.
          Second dictionary: key is the deployment name, value is application name.
      """
      metrics_summary_route = DefaultDict(set)
      metrics_summary_app = DefaultDict(str)
  
      for request_metrics in metrics:
          metrics_summary_route[request_metrics["deployment"]].add(
              request_metrics["route"]
          )
          metrics_summary_app[
              request_metrics["deployment"]
          ] = request_metrics["application"]
      return metrics_summary_route, metrics_summary_app
  
imports: import os
  import sys
  from typing import DefaultDict, Dict, List, Optional
  import grpc
  import pytest
  import requests
  from fastapi import FastAPI
  import ray
  import ray.util.state
  from ray import serve
  from ray._private.test_utils import SignalActor, wait_for_condition
  from ray.serve._private.constants import DEFAULT_LATENCY_BUCKET_MS
  from ray.serve._private.long_poll import LongPollHost, UpdatedObject
  from ray.serve._private.test_utils import ping_fruit_stand, ping_grpc_call_method, ping_grpc_list_applications
  from ray.serve._private.utils import block_until_http_ready
  from ray.serve.config import gRPCOptions
  from ray.serve.handle import DeploymentHandle
  from ray.serve.metrics import Counter, Gauge, Histogram
  from ray.serve.tests.test_config_files.grpc_deployment import g, g2
label_desc: Use image node_id 1 for calling the TestRequestContextMetrics obj's underlying member method code with example usage: obj._generate_metrics_summary(metrics) and returns: metrics_summary_route,  metrics_summary_app