CfgHasState checks that `state` is one of the Configuration's `States`.

CheckValid will validate that there is at least one state, and that the starting state is one of the possible states; further for any of the states it will check that they appear in at least one transition.

HasState will check whether a given state is either origin or destination for the Transition.

NewEvent creates a new Event, with the given `eventName` transition.

UpdateEvent adds the ID and timestamp to the event, if not already set.

Logger is made accessible so that its `Level` can be changed or can be sent to a `NullLog` during testing.

ConfiguredStateMachine is the internal representation of an FSM, which carries within itself the configuration for ease of use.