Used in plugin's registration routine,
        to associate it's detection method with given filesystem id

        Args:
            fs_id: filesystem id that is read from MBR partition entry
            plugin: plugin that supports this filesystem

def register_mbr_plugin(self, fs_id, plugin):
        """Used in plugin's registration routine,
        to associate it's detection method with given filesystem id

        Args:
            fs_id: filesystem id that is read from MBR partition entry
            plugin: plugin that supports this filesystem
        """
        self.logger.debug('MBR: {}, FS ID: {}'
                          .format(self.__get_plugin_name(plugin), fs_id))
        self.__mbr_plugins[fs_id].append(plugin)