object : RequestBody() {
        override fun contentType(): MediaType? {
          return null
        }

        override fun contentLength(): Long {
          return if (uploadKind === TransferKind.CHUNKED) -1L else n.toLong()
        }

        override fun writeTo(sink: BufferedSink) {
          if (writeKind == WriteKind.BYTE_BY_BYTE) {
            for (i in 0 until n) {
              sink.writeByte('x'.code)