Spring WebFlux (Kotlin coRouter) Kotlin

package com.example.pixel

import org.springframework.boot.autoconfigure.SpringBootApplication
import org.springframework.boot.runApplication
import org.springframework.context.annotation.Bean
import org.springframework.http.CacheControl
import org.springframework.http.MediaType
import org.springframework.web.reactive.function.server.bodyValueAndAwait
import org.springframework.web.reactive.function.server.coRouter
import java.util.Base64

private val GIF: ByteArray = Base64.getDecoder().decode("R0lGODlhAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw==")

@SpringBootApplication
class PixelApplication {
    @Bean
    fun pixelRoutes() = coRouter {
        GET("/pixel.gif") {
            ok().contentType(MediaType.IMAGE_GIF)
                .contentLength(GIF.size.toLong())
                .cacheControl(CacheControl.noStore())
                .bodyValueAndAwait(GIF)
        }
    }
}

fun main(args: Array<String>) {
    runApplication<PixelApplication>(*args)
}