*/
  @Throws(IOException::class)
  fun onData(
    streamId: Int,
    source: BufferedSource,
    byteCount: Int,
    last: Boolean,
  ): Boolean

  /** Indicates the reason why this stream was canceled. */
  fun onReset(
    streamId: Int,
    errorCode: ErrorCode,
  )

  companion object {
    @JvmField val CANCEL: PushObserver = PushObserverCancel()