Specify the class, title, and short description of your fetcher plugins.
The title and the description provided are shown within the configuration page.
An associative array whose keys define the fetcher id and whose values contain the fetcher definitions. Each fetcher definition is itself an associative array, with the following key-value pairs:
function hook_aggregator_fetch_info() {
return array(
'aggregator' => array(
'class' => 'Drupal\\aggregator\\Plugin\\aggregator\\fetcher\\DefaultFetcher',
'title' => t('Default fetcher'),
'description' => t('Downloads data from a URL using Drupal\'s HTTP request handler.'),
),
);
}