public static Mono<Void> failedResult(final int code, final String reason, final ServerWebExchange exchange) {
        Object error = ShenyuResultWrap.error(exchange, code, reason, null);
        return WebFluxResultUtils.result(exchange, error);
    }
get failed result.

@param code     code
@param reason   reason
@param exchange exchange
@return the mono.
shenyu-plugin/shenyu-plugin-api/src/main/java/org/apache/shenyu/plugin/api/utils/WebFluxResultUtils.java