Session::save

public function save(): void
{
	$session = $_SESSION;

	$previousHandler = set_error_handler(
		function($type, $msg, $file, $line) use (&$previousHandler) {
			if ($type === E_WARNING && str_starts_with($msg, 'session_write_close():'))
			{
				$handler = $this->sessionHandler;
				$msg = sprintf(
					"session_write_close(): Failed to write session data with "%s" handler",
					$handler? get_class($handler) : ''
				);
			}

			return $previousHandler ? $previousHandler($type, $msg, $file, $line) : false;
		}
	);

	try
	{
		$this->refineReferencesBeforeSave();
		session_write_close();
	}
	finally
	{
		restore_error_handler();
		if ($_SESSION)
		{
			$_SESSION = $session;
		}
	}

	$this->started = false;
}