private List <StateTree> GenerateStateTreesFromFile(string filename)
        {
            List <State>     lst_states     = StateReader.ReadStatesFromFile(filename);
            List <StateTree> lst_statetrees = new List <StateTree>();

            foreach (State s in lst_states)
            {
                lst_statetrees.Add(new StateTree(s));
            }
            return(lst_statetrees);
        }