public static StateConfiguration <TState, TTrigger> PermitReentry <TState, TTrigger>(
            this StateConfiguration <TState, TTrigger> config, TTrigger trigger, Action onTriggerAction)
        {
            Contract.NotNull(onTriggerAction != null, nameof(onTriggerAction));

            return(config.PermitReentry(trigger,
                                        t => onTriggerAction()));
        }
        public static StateConfiguration <TState, TTrigger> PermitReentry <TArgument, TState, TTrigger>(
            this StateConfiguration <TState, TTrigger> config,
            ParameterizedTrigger <TTrigger, TArgument> trigger, Action <TArgument> onTriggerAction)
        {
            Contract.NotNull(onTriggerAction != null, nameof(onTriggerAction));

            return(config.PermitReentry(trigger,
                                        (t, a) => onTriggerAction(a)));
        }