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

  companion object {
    /** Empty request body with no content-type. */
    @JvmField
    val EMPTY: RequestBody = ByteString.EMPTY.toRequestBody()

    /**

  }

  @Test
  fun testFileDescriptor() {
    assertOnFileDescriptor { fd ->
      val requestBody = fd.toRequestBody()

      assertThat(requestBody.contentLength()).isEqualTo(-1L)
      assertThat(requestBody.isOneShot()).isEqualTo(true)
    }
  }

  @Test
  fun testFileDescriptorRead() {
    assertOnFileDescriptor(content = "Hello") { fd ->
      val requestBody = fd.toRequestBody()

      val buffer = Buffer()