parse static method
Implementation
static YoutubeChannelUrl? parse(String url) {
var matches = RegExp(
r'^(?:https?:)?\/\/(?:[A-z]+\.)?youtube.com\/channel\/(?<id>[A-z0-9-\_]+)\/?$')
.allMatches(url);
var id = matches.getValue("id");
if (id == null) return null;
return YoutubeChannelUrl._(id);
}