     (_first_value(query, &#34;code&#34;) is not None and _first_value(query, &#34;state&#34;) is not None)
                or _first_value(query, &#34;error&#34;) is not None
            )
            if is_callback:
                bolt_resp = oauth_flow.handle_callback(bolt_req)
                return to_chalice_response(bolt_resp)
            else:
                bolt_resp = oauth_flow.handle_installation(bolt_req)
                return to_chalice_response(bolt_resp)
    elif method == &#34;POST&#34;: