var myStates = stateMachine(function () {
  this.state('young', { initial: true })
    .state('middleage')
    .state('old')
    .event('age', 'young', 'middleage')
    .event('age', 'middleage', 'old')
    .event('enlightened', ['young', 'middleage', 'old'], 'bliss')
    ;
});

console.log(myState.currentState()); // young
myStates.age();
console.log(myState.currentState()); // middleage
myStates.age();
console.log(myState.currentState()); // old
myStates.enlightened();
console.log(myState.currentState()); // bliss

Pick your poison:

var myStates = stateMachine(function (builder) {
  builder.state('young', { initial: true })
         .event(...)
});

var myStates = stateMachine();

myStates
  .build()
  .state('young', { initial: true })
  .event()
  ...

var myStates = stateMachine();

myStates.build()
  .state('young', { initial: true
                  , leave: function () { /* do stuff */ }
                  , enter: function () { /* do stuff */ }
                  });

myStates.onChange = function (currentStateName, previousStateName) {
  // do stuff
};