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    <h3>Editing: IsInstanceOf.php</h3>
    <textarea name="content" rows="20" cols="80">&lt;?php declare(strict_types=1);
/*
 * This file is part of PHPUnit.
 *
 * (c) Sebastian Bergmann &lt;sebastian@phpunit.de&gt;
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */
namespace PHPUnit\Framework\Constraint;

use function sprintf;
use ReflectionClass;
use ReflectionException;
use SebastianBergmann\RecursionContext\InvalidArgumentException;

/**
 * @no-named-arguments Parameter names are not covered by the backward compatibility promise for PHPUnit
 */
final class IsInstanceOf extends Constraint
{
    /**
     * @var string
     */
    private $className;

    public function __construct(string $className)
    {
        $this-&gt;className = $className;
    }

    /**
     * Returns a string representation of the constraint.
     */
    public function toString(): string
    {
        return sprintf(
            'is instance of %s &quot;%s&quot;',
            $this-&gt;getType(),
            $this-&gt;className,
        );
    }

    /**
     * Evaluates the constraint for parameter $other. Returns true if the
     * constraint is met, false otherwise.
     *
     * @param mixed $other value or object to evaluate
     */
    protected function matches($other): bool
    {
        return $other instanceof $this-&gt;className;
    }

    /**
     * Returns the description of the failure.
     *
     * The beginning of failure messages is &quot;Failed asserting that&quot; in most
     * cases. This method should return the second part of that sentence.
     *
     * @param mixed $other evaluated value or object
     *
     * @throws InvalidArgumentException
     */
    protected function failureDescription($other): string
    {
        return sprintf(
            '%s is an instance of %s &quot;%s&quot;',
            $this-&gt;exporter()-&gt;shortenedExport($other),
            $this-&gt;getType(),
            $this-&gt;className,
        );
    }

    private function getType(): string
    {
        try {
            $reflection = new ReflectionClass($this-&gt;className);

            if ($reflection-&gt;isInterface()) {
                return 'interface';
            }
        } catch (ReflectionException $e) {
        }

        return 'class';
    }
}
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