That's a bit unreadable :-) `called` is misleading, could change to `filterTitle` or something like that. In any case that seems to be a roundabout way of pulling that specific filter to the top, why not something more explicit?

```php
// ... at the end of the function:
// Pull out the "All pages" filter to the top.
unset($allFiltersArray['CMSSiteTreeFilter_Search']);
return array('CMSSiteTreeFilter_Search' => CMSSiteTreeFilter_Search::title()) + $allFiltersArray;
```