newState method
Create a new State for this StateMachine.
name
helps identify the state for debugging purposes.
Implementation
State newState(String name) {
if (_started)
throw IllegalStateMachineMutation(
'Cannot create new state ($name) once the machine has been started.');
State state = State._(name, this);
manageDisposable(state);
_states.add(state);
return state;
}