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);
}