code: def test_pathname_prefix_environ_routes(empty_environ):
      os.environ["DASH_ROUTES_PATHNAME_PREFIX"] = "/routes/"
      _, routes, _ = pathname_configs()
      assert routes == "/routes/"
  
imports: import os
  import logging
  import pytest
  from flask import Flask
  from dash import Dash, exceptions
  from dash._configs import pathname_configs, DASH_ENV_VARS, get_combined_config, load_dash_env_vars
  from dash._utils import AttributeDict
  from dash._get_paths import app_get_asset_url, app_get_relative_path, app_strip_relative_path, get_asset_url, get_relative_path, strip_relative_path
label_desc: Use image node_id 5 for calling a global function with example usage: test_pathname_prefix_environ_routes(empty_environ) without return types