system/classes/Collection.php
public function getIterator() {
        if (!$this->content || $this->contentModified) {
            $this->generateContent();
        }
        return new \ArrayIterator($this->content);
    }
public function getIterator() {
        if (!$this->content || $this->contentModified) {
            $this->generateContent();
        }
        return new \ArrayIterator($this->content);
    }
Returns an ArrayIterator for traversing the contents of the Container.

@return ArrayIterator