func GetEnvelopeFromBlock(data []byte) (*common.Envelope, error) {
	var err error
	env := &common.Envelope{}
	if err = proto.Unmarshal(data, env); err != nil {
		return nil, fmt.Errorf("Error getting envelope(%s)", err)
	}
	return env, nil
}
GetEnvelopeFromBlock gets an envelope from a block's Data field.
package utils
import (
	"errors"
	"fmt"
	"github.com/golang/protobuf/proto"
	"github.com/hyperledger/fabric-sdk-go/third_party/github.com/hyperledger/fabric/protos/common"
	"github.com/hyperledger/fabric-sdk-go/third_party/github.com/hyperledger/fabric/protos/peer"
)