I am evaluating Spring Statemachine and would like 
to understand how to recover from a transition 
error.

I defined an error action for an action executed 
during a transition. The execution of `S1_TO_S2_ACTION`
causes an exception which is handled in `S1_TO_S2_ERROR_HANDLING`.

I can handle the error in the action but how can I recover from 
the error? I tried to send an event in the error handler (`context.getStateMachine().sendEvent(Events.RECOVER)`) but without any effect. 

```java
@Configuration
@EnableStateMachine
class StateMachineConfig
    extends EnumStateMachineConfigurerAdapter<States, Events> {

    Action<States, Events> S1_TO_S2_ERROR_HANDLING = context -> {
        System.out.println(BO + " ERROR!!!");

        System.out.println("E: " + context.getException());
        System.out.println("S: " + context.getSource().getId());
        System.out.println("T: " + context.getTarget().getId());
    };

    @Override
    public void configure(StateMachineTransitionConfigurer<States, Events> transitions)
        throws Exception {

        transitions
        .withExternal()
        .source(States.SI).target(States.S1).event(Events.E1)
        .action(TRANS_ACTION)
        .and()

        .withExternal()            
        .source(States.S1).target(States.S2).event(Events.E2)
        .action(S1_TO_S2_ACTION, S1_TO_S2_ERROR_HANDLING)
        .and()

        .withExternal()
        .source(States.S2).target(States.SE).event(Events.E3)
        .action(TRANS_ACTION);
    }
}

```

Suprisingly calling `stateMachine.hasStateMachineError()` afterwards returns `false`.

Who can I recover in an error action from an error and why does `hasStateMachineError()`
returns `false` if an exception is thrown during a transition?