code: def test_host(self, runner):
      app = Flask(__name__, static_folder=None, host_matching=True)
      app.add_url_rule("/a", host="a", endpoint="a")
      app.add_url_rule("/b", host="b", endpoint="b")
      cli = FlaskGroup(create_app=lambda: app)
      result = runner.invoke(cli, ["routes"])
      assert result.exit_code == 0
      assert "Host" in result.output
  
imports: import importlib.metadata
  import os
  import platform
  import ssl
  import sys
  import types
  from functools import partial
  from pathlib import Path
  import click
  import pytest
  from _pytest.monkeypatch import notset
  from click.testing import CliRunner
  from flask import Blueprint
  from flask import current_app
  from flask import Flask
  from flask.cli import AppGroup
  from flask.cli import find_best_app
  from flask.cli import FlaskGroup
  from flask.cli import get_version
  from flask.cli import load_dotenv
  from flask.cli import locate_app
  from flask.cli import NoAppException
  from flask.cli import prepare_import
  from flask.cli import run_command
  from flask.cli import ScriptInfo
  from flask.cli import with_appcontext
label_desc: Use image node_id 9 for calling the TestRoutes obj's underlying member method code with example usage: obj.test_host(runner) without return types