FSM
Set the initial state of this Finite State Machine.

transitionTo()
Have the FSM schedule a transition for the next update().

immediateTransitionTo()
Have the FSM transit to the next state immediatly.

getCurrentState()
Get the current state of this FSM.

isInState()
Check if this FSM is in the State state.

timeInCurrentState()
Get the current state of this FSM.

update()
Get the current state of this FSM.

State()
Set the initial state of this State.

enter()
Call the userEnter function callback.

update()
Call the userUpdate function callback.

exit()
Call the userExit function callback.