firefly-iii/app/lib/Firefly/Helper/Controllers/Category.php

<?php

namespace Firefly\Helper\Controllers;


use Carbon\Carbon;

class Category implements CategoryInterface
{
    public function journalsInRange(\Category $category, Carbon $start, Carbon $end)
    {
        return $category->transactionjournals()->with(
            ['transactions', 'transactions.account', 'transactiontype', 'components']
        )->orderBy('date', 'DESC')->orderBy('id', 'DESC')->before($end)->after($start)->get();

    }
}