func MustUnmarshal(data []byte, v interface{}) {
	err := json.Unmarshal(data, v)
	if err != nil {
		panic(err)
	}
}
MustUnmarshal behaves like json.Unmarshal but will panic on errors.
package jsonutil  
import "encoding/json"
func MustMarshal(v interface{}) []byte {
	b, err := json.Marshal(v)
	if err != nil {
		panic(err)
	}
	return b
}
func MustMarshalIndent(v interface{}, prefix, indent string) []byte {
	b, err := json.MarshalIndent(v, prefix, indent)
	if err != nil {
		panic(err)
	}
	return b
}