text: """Test N2 GUI with multiple models using Pyppeteer."""
  import sys
  import unittest
  import os
  import urllib.request
  
  # Platform detection adapted from Pyppeteer, used for Pyppeteer's
  # download of a new Chromium revision than the one that breaks
  # on new JavaScript.
  def current_platform() -> str:
      """Get current platform name by short string."""
      if sys.platform.startswith('linux'):
          return 'Linux_x64'
      elif sys.platform.startswith('darwin'):
          return 'Mac'
      elif (sys.platform.startswith('win') or
            sys.platform.startswith('msys') or
            sys.platform.startswith('cyg')):
          if sys.maxsize > 2 ** 31 - 1:
              return 'Win64_x64'
          return 'Win'
      return None
  
  def select_chromium_revision(platform):
      """Grab the current Chromium revision for the specified platform for Pyppeteer."""
      if platform is not None:
          url = 'https://www.googleapis.com/download/storage/v1/b/chromium-browser-snapshots/o/' + \
              platform + '%2FLAST_CHANGE?alt=media'
      
          webf = urllib.request.urlopen(url)
          chromium_revision = bytearray(next(webf)).decode()
  
          print(f'If Pyppeteer cannot find Chromium, install rev. {chromium_revision}')
          os.environ['PYPPETEER_CHROMIUM_REVISION'] = chromium_revision
          download_chromium()
  
  # Make sure Python version is at least 3.6, otherwise do nothing.
  if sys.version_info > (3, 5):
      from pyppeteer.chromium_downloader import check_chromium, download_chromium
      from appdirs import AppDirs
      import shutil
  
      if 'PYPPETEER_CHROMIUM_REINSTALL' in os.environ:
          pyppeteer_chromium_dir = AppDirs('pyppeteer').user_data_dir + '/local-chromium'
          if os.path.isdir(pyppeteer_chromium_dir):
              print("Deleting previous pyppeteer Chromium installation.")
              try:
                  shutil.rmtree(pyppeteer_chromium_dir)
              except:
                  print(f'Deleting old {pyppeteer_chromium_dir} failed.')
          else:
              print(f'{pyppeteer_chromium_dir} does not exist.')
  
      if check_chromium():
          print("Chromium already installed, pyppeteer will not download.")
      else:
          select_chromium_revision(current_platform())
  
      from n2_gui_test import n2_gui_test_case
  
      if __name__ == "__main__":
          unittest.main()
  