How to use the lib0/decoding.js.readVarUint8Array function in lib0

encoding.writeVarUint(encoder, messageSync)
      const syncMessageType = syncProtocol.readSyncMessage(decoder, encoder, doc, room)
      if (syncMessageType === syncProtocol.messageYjsSyncStep2 && !room.synced) {
        syncedCallback()
      }
      if (syncMessageType === syncProtocol.messageYjsSyncStep1) {
        sendReply = true
      }
      break
    case messageQueryAwareness:
      encoding.writeVarUint(encoder, messageAwareness)
      encoding.writeVarUint8Array(encoder, awarenessProtocol.encodeAwarenessUpdate(awareness, Array.from(awareness.getStates().keys())))
      sendReply = true
      break
    case messageAwareness:
      awarenessProtocol.applyAwarenessUpdate(awareness, decoding.readVarUint8Array(decoder), room)
      break
    case messageBcPeerId: {
      const add = decoding.readUint8(decoder) === 1
      const peerName = decoding.readVarString(decoder)
      if (peerName !== room.peerId && ((room.bcConns.has(peerName) && !add) || (!room.bcConns.has(peerName) && add))) {
        const removed = []
        const added = []
        if (add) {
          room.bcConns.add(peerName)
          added.push(peerName)
        } else {
          room.bcConns.delete(peerName)
          removed.push(peerName)
        }
        room.provider.emit('peers', [{
          added,

export const decrypt = (data, key) => {
  if (!key) {
    return /** @type {PromiseLike} */ (promise.resolve(data))
  }
  const dataDecoder = decoding.createDecoder(data)
  const algorithm = decoding.readVarString(dataDecoder)
  if (algorithm !== 'AES-GCM') {
    promise.reject(error.create('Unknown encryption algorithm'))
  }
  const iv = decoding.readVarUint8Array(dataDecoder)
  const cipher = decoding.readVarUint8Array(dataDecoder)
  return crypto.subtle.decrypt(
    {
      name: 'AES-GCM',
      iv
    },
    key,
    cipher
  ).then(data => new Uint8Array(data))
}

export const decrypt = (data, key) => {
  if (!key) {
    return /** @type {PromiseLike} */ (promise.resolve(data))
  }
  const dataDecoder = decoding.createDecoder(data)
  const algorithm = decoding.readVarString(dataDecoder)
  if (algorithm !== 'AES-GCM') {
    promise.reject(error.create('Unknown encryption algorithm'))
  }
  const iv = decoding.readVarUint8Array(dataDecoder)
  const cipher = decoding.readVarUint8Array(dataDecoder)
  return crypto.subtle.decrypt(
    {
      name: 'AES-GCM',
      iv
    },
    key,
    cipher
  ).then(data => new Uint8Array(data))
}

constructor (decoder, id, info) {
    super(decoder, id, info)
    /**
     * @type {Uint8Array}
     */
    this.content = buffer.copyUint8Array(decoding.readVarUint8Array(decoder))
  }
  /**