parse static method
Implementation
static GooglePlusUserNameUrl? parse(String url) {
var matches =
RegExp(r'(?:https?:)?\/\/plus\.google\.com\/\+(?<username>[A-z0-9+]+)')
.allMatches(url);
var username = matches.getValue("username");
if (username == null) return null;
return GooglePlusUserNameUrl._(username);
}