SimplePie_Item::get_source

	 * Get the `<atom:source>` for the item
	 *
	 * @since 1.1
	 * @return SimplePie_Source|null
	 */
	public function get_source()
	{
		if ($return = $this->get_item_tags(SIMPLEPIE_NAMESPACE_ATOM_10, 'source'))
		{
			return $this->registry->create('Source', array($this, $return[0]));
		}