public static void UseInternalSystem()
        {
            InternalSystem internalSystem = new InternalSystem();

            Director robert = new Director("159.753.398-04");

            robert.Name     = "Robert";
            robert.Password = "******";

            AccountManager caroline = new AccountManager("326.985.628-89");

            caroline.Name     = "Caroline";
            caroline.Password = "******";

            CommercialPartner commercialPartner = new CommercialPartner();

            commercialPartner.Password = "******";

            internalSystem.LogInto(robert, "123");
            internalSystem.LogInto(caroline, "abc");
            internalSystem.LogInto(commercialPartner, "123456");
        }