Magento 2 – How to Use the Collection Walk Iterator

Back in Magento 1, it was possible to use the collection iterator to walk through the results and avoid looping through them.

It was a huge improvement in terms of performance when dealing with massive collections.

Here is some sample code of what could be done.

$customers = Mage::getModel('customer/customer')->getCollection()->addAttributeToSelect(array('firstname'), 'inner');
// call iterator walk method with collection query string and callback method as parameters
Mage::getSingleton('core/resource_iterator')->walk($customers->getSelect(), array(array($this, 'customerCallback')));

Then you could define a callback function customerCallback to process the results one by one.

Is that still possible in Magento 2? If so how can I achieve that?