docs: def app(environ, start_response):
      """Simple WSGI application. Returns 200 OK response with 'Hellow world!' in
      the body for GET requests. Returns 405 Method Not Allowed for all other
      methods.
  
      Returns 500 Internal Server Error if an exception is thrown. The response
      body will not include the error or any information about it. The error and
      its stack trace will be reported to FogBugz via BugzScout, though.
  
      :param environ: WSGI environ
      :param start_response: function that accepts status string and headers
      """
      try:
          if environ['REQUEST_METHOD'] == 'GET':
              start_response('200 OK', [('content-type', 'text/html')])
              return ['Hellow world!']
          else:
              start_response(
                  '405 Method Not Allowed', [('content-type', 'text/html')])
              return ['']
      except Exception as ex:
          # Call start_response with exception info.
          start_response(
              '500 Internal Server Error',
              [('content-type', 'text/html')],
              sys.exc_info())
  
          # Record the error to FogBugz and this will return the body for the
          # error response.
          return _handle_exc(ex)