stream buffer piped to fixedSizeChunker then work is done on it

bufferImporter.js

function bufferImporter (buffer, callback) { 
    if(!Buffer.isBuffer(buffer)) { 
      callback('buffer importer must take a buffer')
    }
    const links = [] // { Hash: , Size: , Name: }
    
    var bufferStream = new stream
    bufferStream.push(buffer)
    bufferStream.push(null)

    bufferStream.pipe(new FixedSizeChunker(262145))
    .pipe(through2((chunk, enc, cb) => {
      console.log(chunk)

      // TODO: check if this is right (I believe it should be type 'raw'
      // https://github.com/ipfs/go-ipfs/issues/2331
      const raw = new UnixFS('file', chunk)
      console.log('Size of the chunk '+raw.fileSize())
      const node = new mDAG.DAGNode(raw.marshal())

      dagService.add(node, function (err) {
        if (err) {
          return log.err(err)
        }
        links.push({
          Hash: node.multihash(),
          Size: node.size(),
          leafSize: raw.fileSize(),
          Name: ''
        })

        cb()
      })
    }, (cb) => {
      const file = new UnixFS('file')
      const parentNode = new mDAG.DAGNode()
      links.forEach((l) => {
        file.addBlockSize(l.leafSize)
        const link = new mDAG.DAGLink(l.Name, l.Size, l.Hash)
        parentNode.addRawLink(link)
      })

      parentNode.data = file.marshal()
      dagService.add(parentNode, (err) => {
        if (err) {
          return log.err(err)
        }

        //const pathSplit = path.split('/')
        //const fileName = pathSplit[pathSplit.length - 1]

        callback(null, {
          Hash: parentNode.multihash(),
          Size: parentNode.size()
          //Name: fileName
        }) && cb()
      })
    }))
  }