Multipart request con httpclient5 en Kotlin

@Throws(Exception::class)
fun executeFormMultipartPost(url: String, pathName: String) {
    val client = HttpClients.createDefault()
    val post = HttpPost(url)
    post.addHeader("Accept", "application/json")

    val builder = MultipartEntityBuilder.create()
    builder.addBinaryBody(
        "image", File(
            object {}.javaClass.getResource(pathName).path
        ),
        ContentType.IMAGE_PNG, "file"
    )
    builder.addTextBody("data", "")
    post.entity = builder.build()


    val response = client.execute(post)
    println(EntityUtils.toString(response.entity))
}

fun main(args: Array<String>) {
    println("Hello World!")
    executeFormMultipartPostCustom(
        url = "https://badgecheck.io/results",
        pathName = "baked-badge-image.png"
    )
}

 implementation("org.apache.httpcomponents.client5:httpclient5:5.2.1")

@Throws(Exception::class)
fun executeFormMultipartPostCustom(url: String, pathName: String) {
    val client = HttpClients.createDefault()
    val post = HttpPost(url)
    post.addHeader("Accept", "application/json")
    val decodedBytes = Base64.getDecoder().decode(getImageData())
    val inputStreamBody: InputStreamBody = object : InputStreamBody(
        ByteArrayInputStream(decodedBytes), ContentType.APPLICATION_OCTET_STREAM, "file") {
        override fun getContentLength(): Long {
            return decodedBytes.size.toLong()
        }
    }
    val builder = MultipartEntityBuilder.create()
    builder.addPart("image", inputStreamBody)
    builder.addTextBody("data", "")
    post.entity = builder.build()
    val response = client.execute(post)
    println(EntityUtils.toString(response.entity))
}

fun getImageData(): String {
    return "iVBORw...."
}

{
    "graph": [
        {
            "@context": "https://w3id.org/openbadges/v2",
            "id": "https://api.badgr.io/public/assertions/hAbc4CzwR6i_Z7KKlsIN4g",
            "type": "Assertion",
            "image": "https://api.badgr.io/public/assertions/hAbc4CzwR6i_Z7KKlsIN4g/image",
            "badge": "https://api.badgr.io/public/badges/0I52e1O8Rx-NMSKQoPcktg",
            "issuedOn": "2019-04-11T19:13:34.545808+00:00",
            "narrative": "Awarded by Badgr Pathways",
            "recipient": {
                "type": "email",
                "hashed": true,
                "identity": "sha256$0d3aff1333f840ba142c635ba6b0b2296aebaa0d86889adaa3d5577119e364e4",
                "salt": "ed63e54c6f364ea9b7b4fa1acafc1251"
            },
            "verification": {
                "type": "HostedBadge"
            }
        },
        {
            "@context": "https://w3id.org/openbadges/v2",
            "id": "https://api.badgr.io/public/badges/0I52e1O8Rx-NMSKQoPcktg",
            "type": "BadgeClass",
            "description": "Turing game",
            "image": "https://api.badgr.io/public/badges/0I52e1O8Rx-NMSKQoPcktg/image",
            "tags": [],
            "name": "Mastered Turning Game",
            "alignment": [],
            "criteria": {
                "narrative": "Turing"
            },
            "issuer": "https://api.badgr.io/public/issuers/VSWDm7JjQmOX0ot5BtelLg"
        },
        {
            "@context": "https://w3id.org/openbadges/v2",
            "id": "https://api.badgr.io/public/issuers/VSWDm7JjQmOX0ot5BtelLg",
            "type": "Issuer",
            "description": "An interstellar federal republic, composed of planetary governments that agree to exist semi-autonomously under a single central government based on the principles of universal liberty, rights, and equality, and to share their knowledge and resources in peaceful cooperation, scientific development, space exploration and defensive purposes.",
            "email": "yona@concentricsky.com",
            "image": "https://api.badgr.io/public/issuers/VSWDm7JjQmOX0ot5BtelLg/image",
            "name": "United Federation of Production Software",
            "url": "http://badgr.io"
        }
    ],
    "input": {
        "value": "https://api.badgr.io/public/assertions/hAbc4CzwR6i_Z7KKlsIN4g",
        "input_type": "url"
    },
    "report": {
        "validationSubject": "https://api.badgr.io/public/assertions/hAbc4CzwR6i_Z7KKlsIN4g",
        "openBadgesVersion": "2.0",
        "messages": [],
        "errorCount": 0,
        "warningCount": 0,
        "valid": true
    }
}