code: func newBlockImporter(db database.DB, r io.ReadSeeker) *blockImporter {
  	return &blockImporter{
  		db:           db,
  		r:            r,
  		processQueue: make(chan []byte, 2),
  		doneChan:     make(chan bool),
  		errChan:      make(chan error),
  		quit:         make(chan struct{}),
  		lastLogTime:  time.Now(),
  	}
  }
docs: // newBlockImporter returns a new importer for the provided file reader seeker
  // and database.