set_matched_handler example

        $response = apply_filters( 'rest_request_after_callbacks', $response, $handler, $request );

        if ( is_wp_error( $response ) ) {
            $response = $this->error_to_response( $response );
        } else {
            $response = rest_ensure_response( $response );
        }

        $response->set_matched_route( $route );
        $response->set_matched_handler( $handler );

        return $response;
    }

    /** * Returns if an error occurred during most recent JSON encode/decode. * * Strings to be translated will be in format like * "Encoding error: Maximum stack depth exceeded". * * @since 4.4.0 * * @return false|string Boolean false or string error message. */