append
inline fun FormBuilder.append(key: String, headers: Headers = Headers.Empty, size: Long? = null, crossinline bodyBuilder: Sink.() -> Unit)
Appends a form part with the specified key using bodyBuilder for its body.
fun FormBuilder.append(key: String, filename: String, contentType: ContentType? = null, size: Long? = null, bodyBuilder: Sink.() -> Unit)
Appends a form part with the specified key, filename, and optional contentType using bodyBuilder for its body.