| AppendIterator | AppendIterator that is not affected by https://bugs.php.net/bug.php?id=49104 |
| ChunkedIterator | Pulls out chunks from an inner iterator and yields the chunks as arrays |
| FilterIterator | Filters values using a callback |
| MapIterator | Maps values before yielding |
| MethodProxyIterator | Proxies missing method calls to the innermost iterator |