public void setEventBus(EventBus eventBus) {
        this.eventBus = eventBus;
        afterEventBusSet();
    }
Sets the EventBus used by this {@code SecurityManager} and potentially any of its
children components.
<p/>
After the eventBus attribute has been set, the template method
{@link #afterEventBusSet() afterEventBusSet()} is executed to allow subclasses to adjust when a
eventBus is available.

@param eventBus the EventBus used by this {@code SecurityManager} and potentially any of its
                children components.
@since 1.3
core/src/main/java/org/apache/shiro/mgt/CachingSecurityManager.java