dstBuf := new(bytes.Buffer)
	dst := onlyWriter{dstBuf}
	for i := 0; i < b.N; i++ {
		srcBuf.Reset()
		src.Reset(srcBuf)
		dstBuf.Reset()
		io.Copy(dst, src)
	}
}

func BenchmarkReaderCopyUnoptimal(b *testing.B) {
	// Unoptimal case is where the underlying reader doesn't implement io.WriterTo
	srcBuf := bytes.NewBuffer(make([]byte, 8192))
	src := NewReader(onlyReader{srcBuf})
	dstBuf := new(bytes.Buffer)