func snappyEncode(src []byte) []byte {
	return snappy.Encode(nil, src)
}
SnappyEncode encodes binary data
package sarama
import (
	"bytes"
	"encoding/binary"
	"github.com/golang/snappy"
)
var snappyMagic = []byte{130, 83, 78, 65, 80, 80, 89, 0}