recordsRead  int              // number of records read in current slice
	input        chan *queueItem  // input for workers
	queue        chan *queueItem  // output from workers in order
	err          error            // global error state, only touched by Reader.Read
	bufferPool   sync.Pool        // pool of []byte objects for input
	csvDstPool   sync.Pool        // pool of [][]string used for output

// ETag returns the ETag of the underlying Tagger.
func (r wrapReader) ETag() ETag {
	if r.Tagger == nil {
		return nil
	}
	return r.Tagger.ETag()
}

// Wrap returns an io.Reader that reads from the wrapped
// io.Reader and implements the Tagger interaface.
//
// If content implements Tagger then the returned Reader
// returns ETag of the content. Otherwise, it returns
// nil as ETag.
//