parse static method
Implementation
static StackoverflowUserUrl? parse(String url) {
var matches = RegExp(
r'(?:https?:)?\/\/(?:www\.)?stackoverflow\.com\/users\/(?<id>[0-9]+)\/(?<username>[A-z0-9-_.]+)\/?')
.allMatches(url);
var id = matches.getValue("id");
var username = matches.getValue("username");
if (id == null) return null;
return StackoverflowUserUrl._(id, username);
}