class Logger {
	final String name;
  bool mute = false;
  
  static final Map<String, Logger> _cache = <String, Logger>{};
  
  factory Logger(String name) {
    if(_cache.containsKey(name)) {
      return _cache[name];
    }
    else {
      final logger = Logger._internal(name);
      _cache[name] = logger;
      return logger;
    }
  }
  
  Logger._internal(this.name);
  
  void log(String msg) {
    if(!mute) {
      print(msg);
    }
  }
}

main() {
  var logger = Logger('UI');
  logger.log('Button clicked');
}