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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def authenticate(cls, request, route, server_config):
 """ Ask user for authentication :returns: Response if you need to auth the user otherwise None """

        if not server_config.getboolean("auth", False):
            return

        user = server_config.get("user", "").strip()
        password = server_config.get("password", "").strip()

        if len(user) == 0:
            return

        if "AUTHORIZATION" in request.headers:
            if request.headers["AUTHORIZATION"] == aiohttp.helpers.BasicAuth(user, password, "utf-8").encode():
                return

        log.error("Invalid auth. Username should %s", user)

        response = Response(request=request, route=route)
        response.set_status(401)
        response.headers["WWW-Authenticate"] = 'Basic realm="GNS3 server"'
        # Force close the keep alive. Work around a Qt issue where Qt timeout instead of handling the 401
        # this happen only for the first query send by the client.
        response.force_close()
        return response