View file vendor/illuminate/view/AppendableAttributeValue.php

<?php

namespace Illuminate\View;

class AppendableAttributeValue
{
    /**
     * The attribute value.
     *
     * @var mixed
     */
    public $value;

    /**
     * Create a new appendable attribute value.
     *
     * @param  mixed  $value
     * @return void
     */
    public function __construct($value)
    {
        $this->value = $value;
    }
}