You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: compress.go
    path of file: ./repos/caire/vendor/golang.org/x/image/tiff
    
    the code of the file until where you have to start completion: // Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package tiff

import (
	"bufio"
	"io"
)

type byteReader interface {
	io.Reader
	io.ByteReader
}

// unpackBits decodes the PackBits-compressed data in src and returns the
// uncompressed data.
//
// The PackBits compression format is described in section 9 (p. 42)
// of the TIFF spec.
func unpackBits(r io.Reader) ([]byte, error) {
	buf := make(
    
func unpackBits(r io.Reader) ([]byte, error) {
	buf := make([]byte, 128)
	dst := make([]byte, 0, 1024)
	br, ok := r.(byteReader)
	if !ok {
		br = bufio.NewReader(r)
	}

	for {
		b, err := br.ReadByte()
		if err != nil {
			if err == io.EOF {
				return dst, nil
			}
			return nil, err
		}
		code := int(int8(b))
		switch {
		case code >= 0:
			n, err := io.ReadFull(br, buf[:code+1])
			if err != nil {
				return nil, err
			}
			dst = append(dst, buf[:n]...)
		case code == -128:
			// No-op.
		default:
			if b, err = br.ReadByte(); err != nil {
				return nil, err
			}
			for j := 0; j < 1-code; j++ {
				buf[j] = b
			}
			dst = append(dst, buf[:1-code]...)
		}
	}
}