ZeroQueue = object
  chunks: Deque[Chunk]

proc clear(q: var ZeroQueue) {....raises: [], tags: [].}

proc consumeTo(q: var ZeroQueue; pbytes: pointer; nbytes: int): int {.
    ...raises: [], tags: [].}

proc isEmpty(q: ZeroQueue): bool {....raises: [], tags: [].}

proc len(q: ZeroQueue): int64 {....raises: [], tags: [].}

proc popChunkSeq(q: var ZeroQueue; count: int): seq[byte] {....raises: [], tags: [].}

proc push(q: var ZeroQueue; b: sink seq[byte]) {....raises: [], tags: [].}