public SubjectDAO getSubjectDAO() {
        return subjectDAO;
    }
Returns the {@code SubjectDAO} responsible for persisting Subject state, typically used after login or when an
Subject identity is discovered (e.g. after RememberMe services).  Unless configured otherwise, the default
implementation is a {@link DefaultSubjectDAO}.

@return the {@code SubjectDAO} responsible for persisting Subject state, typically used after login or when an
Subject identity is discovered (e.g. after RememberMe services).
@see DefaultSubjectDAO
@since 1.2
core/src/main/java/org/apache/shiro/mgt/DefaultSecurityManager.java