public function getFlash($identifier = null, $fallback = null) {
		$value = $this->arrayGet(self::$_data, '_session_class._flash.' . $this->section . ($identifier !== null ? '.' . $identifier : ''), $fallback);
		if ($value !== null) {
			$this->arrayDelete(self::$_data, '_session_class._flash.' . $this->section . ($identifier !== null ? '.' . $identifier : ''));
		}
		return $value;
	}