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    <h3>Editing: AttributeBag.php</h3>
    <textarea name="content" rows="20" cols="80">&lt;?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier &lt;fabien@symfony.com&gt;
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Component\HttpFoundation\Session\Attribute;

/**
 * This class relates to session attribute storage.
 *
 * @implements \IteratorAggregate&lt;string, mixed&gt;
 */
class AttributeBag implements AttributeBagInterface, \IteratorAggregate, \Countable
{
    private $name = 'attributes';
    private $storageKey;

    protected $attributes = [];

    /**
     * @param string $storageKey The key used to store attributes in the session
     */
    public function __construct(string $storageKey = '_sf2_attributes')
    {
        $this-&gt;storageKey = $storageKey;
    }

    /**
     * {@inheritdoc}
     */
    public function getName()
    {
        return $this-&gt;name;
    }

    public function setName(string $name)
    {
        $this-&gt;name = $name;
    }

    /**
     * {@inheritdoc}
     */
    public function initialize(array &amp;$attributes)
    {
        $this-&gt;attributes = &amp;$attributes;
    }

    /**
     * {@inheritdoc}
     */
    public function getStorageKey()
    {
        return $this-&gt;storageKey;
    }

    /**
     * {@inheritdoc}
     */
    public function has(string $name)
    {
        return \array_key_exists($name, $this-&gt;attributes);
    }

    /**
     * {@inheritdoc}
     */
    public function get(string $name, $default = null)
    {
        return \array_key_exists($name, $this-&gt;attributes) ? $this-&gt;attributes[$name] : $default;
    }

    /**
     * {@inheritdoc}
     */
    public function set(string $name, $value)
    {
        $this-&gt;attributes[$name] = $value;
    }

    /**
     * {@inheritdoc}
     */
    public function all()
    {
        return $this-&gt;attributes;
    }

    /**
     * {@inheritdoc}
     */
    public function replace(array $attributes)
    {
        $this-&gt;attributes = [];
        foreach ($attributes as $key =&gt; $value) {
            $this-&gt;set($key, $value);
        }
    }

    /**
     * {@inheritdoc}
     */
    public function remove(string $name)
    {
        $retval = null;
        if (\array_key_exists($name, $this-&gt;attributes)) {
            $retval = $this-&gt;attributes[$name];
            unset($this-&gt;attributes[$name]);
        }

        return $retval;
    }

    /**
     * {@inheritdoc}
     */
    public function clear()
    {
        $return = $this-&gt;attributes;
        $this-&gt;attributes = [];

        return $return;
    }

    /**
     * Returns an iterator for attributes.
     *
     * @return \ArrayIterator&lt;string, mixed&gt;
     */
    #[\ReturnTypeWillChange]
    public function getIterator()
    {
        return new \ArrayIterator($this-&gt;attributes);
    }

    /**
     * Returns the number of attributes.
     *
     * @return int
     */
    #[\ReturnTypeWillChange]
    public function count()
    {
        return \count($this-&gt;attributes);
    }
}
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