func errRegionIsStale(region *metapb.Region, origin *metapb.Region) error {
	return errors.Errorf("region is stale: region %v origin %v", region, origin)
}
errRegionIsStale is error info for region is stale.
package core
import (
	"bytes"
	"encoding/hex"
	"fmt"
	"reflect"
	"sort"
	"strings"
	"unsafe"
	"github.com/gogo/protobuf/proto"
	"github.com/pingcap/errors"
	"github.com/pingcap/kvproto/pkg/metapb"
	"github.com/pingcap/kvproto/pkg/pdpb"
	"github.com/pingcap/kvproto/pkg/replication_modepb"
	"github.com/pingcap/log"
	"github.com/tikv/pd/pkg/logutil"
	"go.uber.org/zap"
)