toJson method
Implementation
core.Map<core.String, core.dynamic> toJson() => {
if (buttons != null) 'buttons': buttons!,
if (formattedText != null) 'formattedText': formattedText!,
if (image != null) 'image': image!,
if (subtitle != null) 'subtitle': subtitle!,
if (title != null) 'title': title!,
};