code: function concatBulkBuffer (parser) {
    const list = parser.bufferCache
    const oldOffset = parser.offset
    const length = parser.bigStrSize - oldOffset - 2
    var chunks = list.length
    var offset = parser.bigStrSize - parser.totalChunkSize
    parser.offset = offset
    if (offset <= 2) {
      if (chunks === 2) {
        return list[0].slice(oldOffset, list[0].length + offset - 2)
      }
      chunks--
      offset = list[list.length - 2].length + offset
    }
    resizeBuffer(length)
    const start = bufferOffset
    list[0].copy(bufferPool, start, oldOffset, list[0].length)
    bufferOffset += list[0].length - oldOffset
    for (var i = 1; i < chunks - 1; i++) {
      list[i].copy(bufferPool, bufferOffset)
      bufferOffset += list[i].length
    }
    list[i].copy(bufferPool, bufferOffset, 0, offset - 2)
    bufferOffset += offset - 2
    return bufferPool.slice(start, bufferOffset)
  }
docs: Concat the collected chunks from parser.bufferCache.
  
  Increases the bufferPool size beforehand if necessary.
  
  @param {JavascriptRedisParser} parser
  @returns {Buffer}