toJson method
Creates a json from the object
Implementation
Map toJson() {
return {
'type': type,
'id': id,
'title': title,
'input_message_content': inputMessageContent,
'reply_markup': replyMarkup,
'url': url,
'hide_url': hideUrl,
'description': description,
'thumb_url': thumbUrl,
'thumb_width': thumbWidth,
'thumb_height': thumbHeight,
}..removeWhere((_, v) => v == null);
}