func NewReader(r io.Reader) *Reader {
	if _, ok := r.(io.ByteReader); !ok {
		r = bufio.NewReader(r)
	}
	return &Reader{r: r}
}
NewReader returns a new reader. If r doesn't implement
io.ByteReader, it will be wrapped in a bufio.Reader.
package recordio
import (
	"bufio"
	"encoding/binary"
	"io"
)
type Reader struct {
	r      io.Reader  
	buf    []byte     
	bufcap uint64     
}