def __call__(self, environ, start_response):
        self.start_response = start_response

        # Parse cookies from the WSGI environment
        parsed = parse_cookie(environ)

        # Decode the special zappa cookie if present in the request
        if 'zappa' in parsed:

            # Save the parsed cookies. We need to send them back on every update.
            self.decode_zappa_cookie(parsed['zappa'])

            # Since the client doesn't know it has old cookies,
            # manual expire them.
            self.filter_expired_cookies()

            # Set the WSGI environment cookie to be the decoded value.
            environ[u'HTTP_COOKIE'] = self.cookie_environ_string()
        else:
            # No cookies were previously set
            self.request_cookies = dict()

        # Call the application with our modifier
        response = self.application(environ, self.encode_response)
        
        # If we have a redirect, smash in our response content.
        if self.redirect_content:
            response = [self.redirect_content for item in response]

        # Return the response as a WSGI-safe iterator
        return ClosingIterator(
            response
        )
A note about the zappa cookie: Only 1 cookie can be passed through API
dataset/ETHPy150Open Miserlou/Zappa/zappa/middleware.py/ZappaWSGIMiddleware.__call__