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    <h3>Editing: StreamedResponse.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;

/**
 * StreamedResponse represents a streamed HTTP response.
 *
 * A StreamedResponse uses a callback for its content.
 *
 * The callback should use the standard PHP functions like echo
 * to stream the response back to the client. The flush() function
 * can also be used if needed.
 *
 * @see flush()
 *
 * @author Fabien Potencier &lt;fabien@symfony.com&gt;
 */
class StreamedResponse extends Response
{
    protected $callback;
    protected $streamed;
    private bool $headersSent;

    /**
     * @param int $status The HTTP status code (200 &quot;OK&quot; by default)
     */
    public function __construct(callable $callback = null, int $status = 200, array $headers = [])
    {
        parent::__construct(null, $status, $headers);

        if (null !== $callback) {
            $this-&gt;setCallback($callback);
        }
        $this-&gt;streamed = false;
        $this-&gt;headersSent = false;
    }

    /**
     * Sets the PHP callback associated with this Response.
     *
     * @return $this
     */
    public function setCallback(callable $callback): static
    {
        $this-&gt;callback = $callback;

        return $this;
    }

    /**
     * This method only sends the headers once.
     *
     * @return $this
     */
    public function sendHeaders(): static
    {
        if ($this-&gt;headersSent) {
            return $this;
        }

        $this-&gt;headersSent = true;

        return parent::sendHeaders();
    }

    /**
     * This method only sends the content once.
     *
     * @return $this
     */
    public function sendContent(): static
    {
        if ($this-&gt;streamed) {
            return $this;
        }

        $this-&gt;streamed = true;

        if (null === $this-&gt;callback) {
            throw new \LogicException('The Response callback must not be null.');
        }

        ($this-&gt;callback)();

        return $this;
    }

    /**
     * @return $this
     *
     * @throws \LogicException when the content is not null
     */
    public function setContent(?string $content): static
    {
        if (null !== $content) {
            throw new \LogicException('The content cannot be set on a StreamedResponse instance.');
        }

        $this-&gt;streamed = true;

        return $this;
    }

    public function getContent(): string|false
    {
        return false;
    }
}
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