Laravel Translatable factory seeding with dynamic locales

I want to factory seed a translatable model without hardcoding the locales.

There are two values that I have to seed, slug which is not translatable, and title which has to be translated to all the languages from the languages table.

Here is the factory file:

$factory->define(App\Category::class, function (Faker $faker) {

 $counter = 1;
 $locales = Language::pluck('lang'); //returns hr,en,de
 $titles = [];

 foreach ($locales as $locale) {
    $titles[$locale] = [
        'title' => 'Title for category-' .$counter++. ' on '. $locale . ' language'
    ];
 }

/*
$titles = 
     "hr" => array:1 [
        "title" => "Title for category-1 on hr language"
     ]
     "en" => array:1 [
        "title" => "Title for category-2 on en language"
      ...
 */

return [
    'slug' => 'category-'.$counter++,
    $titles
];
});

This gives me an error:

Column not found: 1054 Unknown column 'hr'

Query created by the factory:

insert in to category_translations (locale, hr, en, de, test, category_id) values (0, Title for category-1 on hr language, Title for category-2 on en language, Title for category-3 on de languag e, Title for category-4 on test language, 20))

via Chebli Mohamed