How to use the big-integer.max function in big-integer

let isEnd = true
    if (messages.length === count + 1) {
      // We intentionally included another message to see if we are at the end.
      // We are not.
      isEnd = false
      messages.splice(messages.length - 1, 1)
    }

    const lastMessage = messages[messages.length - 1]
    const nextPosition = forward
      ? BigInteger(lastMessage.position)
          .plus(BigInteger.one)
          .toString()
      : // nextVersion will be 0 at the end, but that always includes the first message in
        // the stream. There's no way around this that does not skip the first message.
        BigInteger.max(
          BigInteger(lastMessage.position).minus(BigInteger.one),
          BigInteger(-1)
        ).toString()

    return {
      isEnd,
      nextPosition,
      messages: await maybeFilterExpiredMessages(messages)
    }
  }

function readAllBackward(startIndex: number, count: number): ReadAllResult {
    const slice = inMemoryAllStream.slice(
      Math.max(0, startIndex - count),
      startIndex + 1
    )

    const isEnd = slice.length < count + 1
    if (!isEnd) {
      slice.splice(0, 1)
    }
    const lastMessage = slice.length > 0 ? slice[0] : null
    slice.reverse()
    return {
      isEnd,
      messages: slice.map(m => toStreamMessage(m)),
      nextPosition: BigInteger.max(
        BigInteger(-1),
        isEnd
          ? BigInteger(-1)
          : BigInteger(lastMessage!.position).minus(BigInteger(1))
      ).toString()
    }
  }