code: func (rp *ReaderPool) Put(br *bufio.Reader) {
  	// Should reset even if we do Reset() inside Get().
  	// This is done to prevent locking underlying io.Reader from GC.
  	br.Reset(nil)
  	rp.pool.Put(br, readerSize(br))
  }
docs: // Put takes ownership of bufio.Reader for further reuse.