default IStateMachine.EventApi event() {
    return (IStateMachine.EventApi) this;
  }
Get the {@link IStateMachine.EventApi} object.

<p>If this {@link IStateMachine} chooses to support the optional {@link
IStateMachine.EventApi}, it may either implement {@link IStateMachine.EventApi} directly or
override this method to return an {@link IStateMachine.EventApi} object.

@return The {@link IStateMachine.EventApi} object.
iotdb-core/consensus/src/main/java/org/apache/iotdb/consensus/IStateMachine.java