code: def prerequisite_check():
      
  
      # Check Python version
      if sys.version_info < (3, 6):
          version_str = "%s.%s.%s" % sys.version_info[:3]
          # TRANSLATORS: This word is used as a part of search query suggested to users,
          # it may appears in context like "Ubuntu 16.04 install Python 3.7"
          search_url = build_search_query(_("install") + " Python 3.7")
          return _("EH Forwarder Bot requires a minimum of Python 3.6 to run.  You "
                   "are currently using Python {version}. \n"
                   "\n"
                   "You may want to try:\n"
                   "{url}").format(version=version_str, url=search_url)
  
      # Check installations of modules
      modules_err = _("You may want to visit the modules repository to find a list of "
                      "available modules to install.\n"
                      "https://github.com/blueset/ehForwarderBot/wiki/Channels-Repository")
      # 1. At least 1 master channel must be installed
      try:
          next(pkg_resources.iter_entry_points("ehforwarderbot.master"))
      except StopIteration:
          return _("No master channel detected.  EH Forwarder Bot requires at least one "
                   "master channel installed to run.") + "\n\n" + modules_err
  
      # 2. At least 1 slave channel must be installed
      try:
          next(pkg_resources.iter_entry_points("ehforwarderbot.slave"))
      except StopIteration:
          return _("No slave channel detected.  EH Forwarder Bot requires at least one "
                   "slave channel installed to run.") + "\n\n" + modules_err
docs: Check prerequisites of the framework, including Python version, installation of
      modules, etc.
  
      Returns:
          Optional[str]: If the check is not passed, return error message regarding
              failed test case.  None is returned otherwise.