View file vendor/illuminate/container/Util.php

<?php

namespace Illuminate\Container;

use Closure;

class Util
{
    /**
     * If the given value is not an array and not null, wrap it in one.
     *
     * From Arr::wrap() in Illuminate\Support.
     *
     * @param  mixed  $value
     * @return array
     */
    public static function arrayWrap($value)
    {
        if (is_null($value)) {
            return [];
        }

        return is_array($value) ? $value : [$value];
    }

    /**
     * Return the default value of the given value.
     *
     * From global value() helper in Illuminate\Support.
     *
     * @param  mixed  $value
     * @return mixed
     */
    public static function unwrapIfClosure($value)
    {
        return $value instanceof Closure ? $value() : $value;
    }
}