public void deleteExpiredSessions(int maxSessionsToDelete) {
        tenantRepository.getAllTenants()
                .forEach(tenant -> tenant.getSessionRepository().deleteExpiredRemoteAndLocalSessions(session -> sessionIsActiveForItsApplication(tenant, session),
                                                                                                     maxSessionsToDelete));
    }
Gets the active Session for the given application id.

@return the active session, or null if there is no active session for the given application id.
configserver/src/main/java/com/yahoo/vespa/config/server/ApplicationRepository.java