public static HashSet <Kolokvij> GetValuesForKolokvijs(string fileName)
        {
            HashSet <Kolokvij>         entities = new HashSet <Kolokvij>();
            DatotekaCreator <Kolokvij> dc       = (DatotekaCreator <Kolokvij>) new KolokvijConcreteCreator();
            DatotekaProduct <Kolokvij> dp       = dc.CreateProduct();

            entities = dp.GetEntities(fileName);
            return(entities);
        }
        public static HashSet <Profesor> GetValuesForProfesors(string fileName)
        {
            HashSet <Profesor>         entities = new HashSet <Profesor>();
            DatotekaCreator <Profesor> dc       = (DatotekaCreator <Profesor>) new ProfesorConcreteCreator();
            DatotekaProduct <Profesor> dp       = dc.CreateProduct();

            entities = dp.GetEntities(fileName);
            return(entities);
        }
        public static HashSet <Dvorana> GetValuesForDvoranas(string fileName)
        {
            HashSet <Dvorana>         entities = new HashSet <Dvorana>();
            DatotekaCreator <Dvorana> dc       = (DatotekaCreator <Dvorana>) new DvoranaConcreteCreator();
            DatotekaProduct <Dvorana> dp       = dc.CreateProduct();

            entities = dp.GetEntities(fileName);
            return(entities);
        }
        public static HashSet <Student> GetValuesForStudents(string fileName)
        {
            HashSet <Student>         entities = new HashSet <Student>();
            DatotekaCreator <Student> dc       = (DatotekaCreator <Student>) new StudentConcreteCreator();
            DatotekaProduct <Student> dp       = dc.CreateProduct();

            entities = dp.GetEntities(fileName);
            return(entities);
        }