Comment on: "docs-php-library/tutorial/collation.txt"

return $this->posts->aggregate(

            [

                [

                    '$lookup' => [

                        'from' => 'authors',

                        'localField' => 'author_id',

                        'foreignField' => '_id',

                        'as' => 'author',

                    ],

                ],

                ['$limit' => 5],

                ['$skip' => 0],

                ['$sort' => ['created_at' => -1]]

            ],

            [

            ]

)->toArray();