private void ClearRegion(string regionName)
    {
        _sessionFactory.EvictQueries(regionName);

        foreach (var collectionMetaData in _sessionFactory.GetAllCollectionMetadata().Values)
        {
            var collectionPersister = collectionMetaData as NHibernate.Persister.Collection.ICollectionPersister;
            if (collectionPersister != null)
            {
                if ((collectionPersister.Cache != null) && (collectionPersister.Cache.RegionName == regionName))
                {
                    _sessionFactory.EvictCollection(collectionPersister.Role);
                }
            }
        }

        foreach (var classMetaData in _sessionFactory.GetAllClassMetadata().Values)
        {
            var entityPersister = classMetaData as NHibernate.Persister.Entity.IEntityPersister;
            if (entityPersister != null)
            {
                if ((entityPersister.Cache != null) && (entityPersister.Cache.RegionName == regionName))
                {
                    _sessionFactory.EvictEntity(entityPersister.EntityName);
                }
            }
        }
    }