laravel_sketch/app/Console/Commands/TestCommand.php

<?php

namespace App\Console\Commands;

use Illuminate\Console\Command;
use Nerd\CartesianProduct\CartesianProduct;

class TestCommand extends Command
{
    /**
     * The name and signature of the console command.
     *
     * @var string
     */
    protected $signature = 'test';

    /**
     * The console command description.
     *
     * @var string
     */
    protected $description = 'Command description';

    /**
     * Execute the console command.
     *
     * @return int
     */
    public function handle()
    {
        $cartesianProduct = new CartesianProduct();
        $cartesianProduct->appendSet(["a"]);
        dump($cartesianProduct->compute());
        $cartesianProduct = new CartesianProduct();
        $cartesianProduct->appendSet(["a"]);
        $cartesianProduct->appendSet(["b"]);
        dump($cartesianProduct->compute());
    }
}