public static StrictCirclingGroup Instance(float radius, float speed, string group)
 {
     var key = new Tuple<float, float, string>(radius, speed, group);
     StrictCirclingGroup ret;
     if (!instances.TryGetValue(key, out ret))
         ret = instances[key] = new StrictCirclingGroup(radius, speed, group);
     return ret;
 }
        public static StrictCirclingGroup Instance(float radius, float speed, string group)
        {
            var key = new Tuple <float, float, string>(radius, speed, group);
            StrictCirclingGroup ret;

            if (!instances.TryGetValue(key, out ret))
            {
                ret = instances[key] = new StrictCirclingGroup(radius, speed, group);
            }
            return(ret);
        }