protected void applyCacheManagerToSessionManager() {
        if (this.sessionManager instanceof CacheManagerAware) {
            ((CacheManagerAware) this.sessionManager).setCacheManager(getCacheManager());
        }
    }
Ensures the internal delegate <code>SessionManager</code> is injected with the newly set
{@link #setCacheManager CacheManager} so it may use it for its internal caching needs.
<p/>
Note:  This implementation only injects the CacheManager into the SessionManager if the SessionManager
instance implements the {@link CacheManagerAware CacheManagerAware} interface.
core/src/main/java/org/apache/shiro/mgt/SessionsSecurityManager.java