Eloquent loaded with relations - eloquent

Question

class Market extends Model{
protected $table = 'Markets';
protected $primaryKey = 'maid';
protected $guarded = ['maid'];
protected $casts = ['trade' => 'boolean'];
protected $with = ['textbook'];
public $timestamps = false;
public function textbook(){
return $this->hasMany(Textbook::class, 'isbn13', 'isbn13');
}
}
class MarketController extends Controller{
public function get($request, $response){
$market = Market::with('textbook')->paginate();
return $response->withJson($market);
}
}
I have an Eloquent Collection with some relations let's say Market and Textbook. I have the relations working just fine. My question is how can I modify my collection to be nested. That is, right now it returns the information about the book and then I can load the relation textbook.
Currently I have:
{
"maid": 1,
"meid": 388,
"coid": 139719,
"isbn13": "9780718197049",
"quality": 8,
"price": 99,
"trade": 0,
"notes": "Brand new book at used price!",
"timecard": "2018-01-08 07:38:38",
"textbook": []
}
But I want something like this:
{
"maid": 1,
"meid": 388,
"coid": 139719,
"isbn13": "9780718197049",
"quality": 8,
"price": 99,
"trade": 0,
"notes": "Brand new book at used price!",
"timecard": "2018-01-08 07:38:38",
"textbook": [
{
"isbn13": 2147483647,
"isbn10": "0718197046",
"title": "Economics: The User's Guide",
"subtitle": "A Pelican Introduction",
"authors": "Ha-joon Chang",
"publisher": "Penguin UK",
"published": "2014-05-01",
"edition": null,
"volume": null,
"pages": 304,
"categories": "Business & Economics",
"description": "What is economics? What can - and can't - it explain about the world? Why does it matter? Ha-Joon Chang teaches economics at Cambridge University, and writes a column for the Guardian. The Observer called his book 23 Things They Don't Tell You About Capitalism, which was a no.1 bestseller, 'a witty and timely debunking of some of the biggest myths surrounding the global economy.' He won the Wassily Leontief Prize for advancing the frontiers of economic thought, and is a vocal critic of the failures of our current economic system.",
"thumbnail": "http://books.google.com/books/content?id=93rAAgAAQBAJ&printsec=frontcover&img=1&zoom=1&edge=curl&source=gbs_api"
}
]
}
How do I accomplish the above (nested) result and where I place that code!