Online PHP editor | output for BZUJr

<?php function setPrevious(Throwable $e, Throwable $previous): Throwable { try { try { throw $previous; } finally { throw $e; } } catch (Throwable $e) { return $e; } } class SimpleException extends Exception { public function __construct($message) { parent::__construct($message); } } $a = new SimpleException('A'); $b = new SimpleException('B'); $c = new SimpleException('C'); setPrevious($a, $b); setPrevious($a, $c); $e = $a; do { var_dump($e->getMessage()); } while ($e = $e->getPrevious());