override fun contentLength() = -1L

  override fun writeTo(sink: BufferedSink) {
    GzipSink(sink).buffer().use(delegate::writeTo)
  }

  override fun isOneShot() = delegate.isOneShot()

   *  * A retryable server failure (HTTP 503 with a `Retry-After: 0` response header).
   *  * A misdirected request (HTTP 421) on a coalesced connection.
   */
  open fun isOneShot(): Boolean = false

  /**
   * Returns the SHA-256 hash of this [RequestBody]
   */
  @Throws(IOException::class)
  fun sha256(): ByteString {
    val hashingSink = HashingSink.sha256(blackholeSink())