Laravel 5.1 Base Model - adds defaults to $casts property on __construct

Model.php

<?php

namespace App;

use Illuminate\Database\Eloquent\Model as Eloquent;

class Model extends Eloquent
{
    /**
     * Create a new Eloquent model instance.
     *
     * @param array $attributes
     */
    public function __construct(array $attributes = [])
    {
        $this->casts = array_merge([
            'id' => 'integer',
            'user_id' => 'integer',
        ], $this->casts);

        parent::__construct($attributes);
    }
}