InstallerException.php

<?php

namespace Drupal\Core\Installer\Exception;

use Drupal\Core\StringTranslation\StringTranslationTrait;

/**
 * Base class for exceptions thrown by installer.
 */
class InstallerException extends \RuntimeException {
    use StringTranslationTrait;
    
    /**
     * The page title to output.
     *
     * @var string
     */
    protected $title;
    
    /**
     * Constructs a new installer exception.
     *
     * @param string $message
     *   The exception message.
     * @param string $title
     *   (optional) The page title. Defaults to 'Error'.
     * @param int $code
     *   (optional) The exception code. Defaults to 0.
     * @param \Exception $previous
     *   (optional) A previous exception.
     */
    public function __construct($message, $title = 'Error', $code = 0, \Exception $previous = NULL) {
        parent::__construct($message, $code, $previous);
        $this->title = $title;
    }
    
    /**
     * Returns the exception page title.
     *
     * @return string
     */
    public function getTitle() {
        return $this->title;
    }

}