Change record status: 
Introduced in branch: 

The aggregator_feed_items_load() function (also named aggregator_load_feed_items() for part of the 8.x development cycle) has been split up and moved to 3 separate methods in \Drupal\aggregator\ItemStorageControllerInterface.

In Drupal 7:

// Loads all feed items.
$items = aggregator_feed_items_load('sum');

// Loads feed items filtered by feed 'source'.  $feed object contains a fid property for the feed ID.
$items = aggregator_feed_items_load('source', $feed);

// Loads feed items filtered by feed category. $category array contains a cid key for the category ID.
$items = aggregator_feed_items_load('category', $category);

In Drupal 8

// Get the ItemStorageController from the dependency injection container.
$storage_controller = Drupal::entityManager()->getStorageController('aggregator_item');

// Loads all feed items.

// Loads feed items by feed ID ($fid).

// Loads feed items by Category ID ($cid).

Module developers
Updates Done (doc team, etc.)
Online documentation: 
Not done
Theming guide: 
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Module developer documentation: 
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Examples project: 
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Coder Review: 
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Coder Upgrade: 
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Other updates done