update method
Implementation
Future<void> update(String templateId, String text,
{String cssClass = '', bool textEditable = false}) async {
final url = apiPath['flairtemplate']
.replaceAll(_kSubredditRegExp, _subreddit.displayName);
final data = <String, String>{
'api_type': 'json',
'css_class': cssClass,
'flair_template_id': templateId,
'text': text,
'text_editable': textEditable.toString(),
};
await _subreddit.reddit.post(url, data);
}