code: func getStruct(s interface{}) reflect.Value {
  	in := reflect.Indirect(reflect.ValueOf(s))
  	if in.Kind() != reflect.Struct {
  		panic(fmt.Sprintf("s must be a sturct, not %s\n", in.Kind()))
  	}
  	return in
  }
docs: // getStruct panics if s is not a struct. Returns the reflect.Indirect(reflect.ValueOf(s))