br := NewReader(strings.NewReader("example"))
	br.WriteTo(io.Discard)
	if err := br.UnreadRune(); err == nil {
		t.Error("UnreadRune didn't fail after WriteTo")
	}
}

func TestNoUnreadByteAfterWriteTo(t *testing.T) {
	br := NewReader(strings.NewReader("example"))
	br.WriteTo(io.Discard)
	if err := br.UnreadByte(); err == nil {
		t.Error("UnreadByte didn't fail after WriteTo")
	}
}

    override fun contentType(): MediaType? {
      return "text/plain".toMediaType()
    }

    override fun contentLength(): Long {
      return chunk!!.size * 8L
    }

    override fun writeTo(sink: BufferedSink) {
      try {
        var i = 0
        while (i < contentLength()) {
          sink.write(chunk!!)
          sink.flush()
          Thread.sleep(100)
          i += chunk.size

          url = server.url("/foo"),
          body =
            object : RequestBody() {
              override fun contentType(): MediaType = "text/plain; charset=utf-8".toMediaType()

              override fun writeTo(sink: BufferedSink) {
                sink.write(postBytes)
              }
            },
        ),
      )
    val response = call.execute()
    assertThat(response.body.string()).isEqualTo("ABCDE")

	public final fun encodedValue (I)Ljava/lang/String;
	public final fun name (I)Ljava/lang/String;
	public final fun size ()I
	public final fun value (I)Ljava/lang/String;
	public fun writeTo (Lokio/BufferedSink;)V
}

public final class okhttp3/FormBody$Builder {
	public fun <init> ()V
	public fun <init> (Ljava/nio/charset/Charset;)V

    This simple option dramatically changes the behavior of the request body and of the entire
    call.

    The `RequestBody.writeTo()` method may now retain a reference to the provided sink and
    hand it off to another thread to write to it after `writeTo` returns.

    The `EventListener` may now see requests and responses interleaved in ways not previously

	reader := bytes.NewReader(data)
	for {
		// Using io.Copy instead of this loop will not work for us as io.Copy
		// will use bytes.Reader.WriteTo() which will not do shardSize'ed writes
		// causing error.
		n, err := reader.Read(shard)
		w.Write(shard[:n])
		if err == nil {
			continue
		}
		if err == io.EOF {
			break
		}