code: function writev (chunks, cb) {
      var buffers = new Array(chunks.length)
      for (var i = 0; i < chunks.length; i++) {
        if (typeof chunks[i].chunk === 'string') {
          buffers[i] = Buffer.from(chunks[i], 'utf8')
        } else {
          buffers[i] = chunks[i].chunk
        }
      }
  
      this._write(Buffer.concat(buffers), 'binary', cb)
    }
docs: this is to be enabled only if objectMode is false