StateMachineDefinition.groovy

    static Cell transition(event, Cell cell) {
        List states = state_machine_definition[cell.state]
        def transition = states.find { it.event == event }

        if (!transition) {
            throw new Exception("invalid event $event for state ${cell.state}")
        }

        Cell tempCell = new Cell(transition.to, cell.lifeLong)

        if (transition.afterAction) {
            tempCell."${transition.afterAction}"()
        }

        return tempCell
    }