buf := NewBuffer(make([]byte, n))
	for i := 0; i < b.N; i++ {
		buf.Reset()
		for i := 0; i < n; i++ {
			buf.WriteByte('x')
		}
	}
}

func BenchmarkWriteRune(b *testing.B) {
	const n = 4 << 10
	const r = '☺'
	b.SetBytes(int64(n * utf8.RuneLen(r)))
	buf := NewBuffer(make([]byte, n*utf8.UTFMax))
	for i := 0; i < b.N; i++ {
		buf.Reset()
		for i := 0; i < n; i++ {
			buf.WriteRune(r)
		}
	}
}

				tw.WriteHeader(file.hdr)
				tw.Write(file.body)
			}
			tw.Close()
			b.Run(v.label, func(b *testing.B) {
				b.ReportAllocs()
				// Read from the byte buffer.
				for i := 0; i < b.N; i++ {
					r.Reset(buf.Bytes())
					tr := NewReader(&r)
					if _, err := tr.Next(); err != nil {
						b.Errorf("unexpected Next error: %v", err)
					}
					if _, err := io.Copy(io.Discard, tr); err != nil {