问题：使用proto Unmarshal报错，提示以下信息：

cannot use promoRule (variable of type *db.PromotionRuleSet) as protoreflect.ProtoMessage value in argument to proto.Unmarshal: missing method ProtoReflect (compile)

解决方法：
import的包从

"google.golang.org/protobuf/proto"

改成

"github.com/golang/protobuf/proto"