for level := BestSpeed; level <= BestCompression; level++ {
			testLevelDict(t, tag, b, level, "")
		}
	}
}

func TestWriterBig(t *testing.T) {
	for i, fn := range filenames {
		testFileLevelDict(t, fn, DefaultCompression, "")
		testFileLevelDict(t, fn, NoCompression, "")
		testFileLevelDict(t, fn, HuffmanOnly, "")
		for level := BestSpeed; level <= BestCompression; level++ {
			testFileLevelDict(t, fn, level, "")

// "compress/gzip" does not also have to import "compress/flate".
const (
	NoCompression      = flate.NoCompression
	BestSpeed          = flate.BestSpeed
	BestCompression    = flate.BestCompression
	DefaultCompression = flate.DefaultCompression
	HuffmanOnly        = flate.HuffmanOnly
)

// A Writer is an io.WriteCloser.
// Writes to a Writer are compressed and written to w.
type Writer struct {

// "compress/zlib" does not also have to import "compress/flate".
const (
	NoCompression      = flate.NoCompression
	BestSpeed          = flate.BestSpeed
	BestCompression    = flate.BestCompression
	DefaultCompression = flate.DefaultCompression
	HuffmanOnly        = flate.HuffmanOnly
)

// A Writer takes data written to it and writes the compressed

	for _, level := range []int{BestSpeed, BestCompression, DefaultCompression, HuffmanOnly} {
		b := bytes.NewBuffer(nil)
		w, err := NewWriterLevel(b, level)
		if err != nil {
			f.Fatalf("failed to construct writer: %s", err)
		}
		_, err = w.Write(inp)

		}
		img, typ, err := image.Decode(bytes.NewReader(b))
		if err != nil || typ != "png" {
			return
		}
		levels := []CompressionLevel{
			DefaultCompression,
			NoCompression,
			BestSpeed,
			BestCompression,
		}
		for _, l := range levels {
			var w bytes.Buffer
			e := &Encoder{CompressionLevel: l}
			err = e.Encode(&w, img)
			if err != nil {
				t.Errorf("failed to encode valid image: %s", err)
				continue

	// Create a new zip archive.
	w := zip.NewWriter(buf)

	// Register a custom Deflate compressor.
	w.RegisterCompressor(zip.Deflate, func(out io.Writer) (io.WriteCloser, error) {
		return flate.NewWriter(out, flate.BestCompression)
	})

	// Proceed to add files to w.

		}
	})
}

var levelTests = []struct {
	name  string
	level int
}{
	{"Huffman", HuffmanOnly},
	{"Speed", BestSpeed},
	{"Default", DefaultCompression},
	{"Compression", BestCompression},
}

var sizes = []struct {
	name string
	n    int
}{
	{"1e4", 1e4},
	{"1e5", 1e5},
	{"1e6", 1e6},
}

func doBench(b *testing.B, f func(b *testing.B, buf []byte, level, n int)) {

	switch l {
	case DefaultCompression:
		return zlib.DefaultCompression
	case NoCompression:
		return zlib.NoCompression
	case BestSpeed:
		return zlib.BestSpeed
	case BestCompression:
		return zlib.BestCompression
	default:
		return zlib.DefaultCompression
	}
}

func (e *encoder) writeIEND() { e.writeChunk(nil, "IEND") }

// Encode writes the Image m to w in PNG format. Any Image may be

			extra := ""
			if f.Name != "" {
				extra = " " + f.Name
			}
			log.Fatalf("writing %s%s: %v", name, extra, err)
		}
	}()

	zw := check(gzip.NewWriterLevel(out, gzip.BestCompression))
	tw := tar.NewWriter(zw)

	// Find the mode and mtime to use for directory entries,
	// based on the mode and mtime of the first file we see.
	// We know that modes and mtimes are uniform across the archive.

		}
		gzw := gzip.NewWriter(writer)
		defer gzw.Close()
		writer = gzw
	case "deflate":
		var err error
		reader = flate.NewReader(reader)
		flw, err := flate.NewWriter(writer, flate.BestCompression)
		if err != nil {
			return nil, fmt.Errorf("errorf making flate writer: %v", err)
		}
		defer func() {
			flw.Close()
			flw.Flush()
		}()
		writer = flw
	case "":
		// This is fine