code: func (f FindInMapFunc) MarshalJSON() ([]byte, error) {
  	return json.Marshal(struct {
  		FnFindInMap []interface{} `json:"Fn::FindInMap"`
  	}{FnFindInMap: []interface{}{f.MapName, f.TopLevelKey, f.SecondLevelKey}})
  }
docs: // MarshalJSON returns a JSON representation of the object