public OrchardQueryable(ContentTypeDefinition type, OrchardQueryProvider orchardQueryProvider, Expression expression)
        {
            _type = type;

            Provider    = orchardQueryProvider;
            Expression  = expression;
            ElementType = typeof(ContentItem);
        }
        public OrchardQueryable(ContentTypeDefinition type, OrchardDataSource dataSource)
        {
            _type       = type;
            _dataSource = dataSource;

            Provider    = new OrchardQueryProvider(type, _dataSource);
            Expression  = Expression.Constant(this);
            ElementType = typeof(ContentItem);
        }