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    <h3>Editing: HelperSet.php</h3>
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/*
 * 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\Console\Helper;

use Symfony\Component\Console\Exception\InvalidArgumentException;

/**
 * HelperSet represents a set of helpers to be used with a command.
 *
 * @author Fabien Potencier &lt;fabien@symfony.com&gt;
 *
 * @implements \IteratorAggregate&lt;string, HelperInterface&gt;
 */
class HelperSet implements \IteratorAggregate
{
    /** @var array&lt;string, HelperInterface&gt; */
    private array $helpers = [];

    /**
     * @param HelperInterface[] $helpers
     */
    public function __construct(array $helpers = [])
    {
        foreach ($helpers as $alias =&gt; $helper) {
            $this-&gt;set($helper, \is_int($alias) ? null : $alias);
        }
    }

    public function set(HelperInterface $helper, string $alias = null)
    {
        $this-&gt;helpers[$helper-&gt;getName()] = $helper;
        if (null !== $alias) {
            $this-&gt;helpers[$alias] = $helper;
        }

        $helper-&gt;setHelperSet($this);
    }

    /**
     * Returns true if the helper if defined.
     */
    public function has(string $name): bool
    {
        return isset($this-&gt;helpers[$name]);
    }

    /**
     * Gets a helper value.
     *
     * @throws InvalidArgumentException if the helper is not defined
     */
    public function get(string $name): HelperInterface
    {
        if (!$this-&gt;has($name)) {
            throw new InvalidArgumentException(sprintf('The helper &quot;%s&quot; is not defined.', $name));
        }

        return $this-&gt;helpers[$name];
    }

    public function getIterator(): \Traversable
    {
        return new \ArrayIterator($this-&gt;helpers);
    }
}
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