“StormHDFS连接器”的源代码，可用于将数据写入hdfs。github url是：https://github.com/ptgoetz/storm-hdfs 有一种特殊的拓扑：“hdfsfiletopology”用于将“|”分隔的数据写入hdfs。链接：https://github.com/ptgoetz/storm-hdfs/blob/master/src/test/java/org/apache/storm/hdfs/bolt/hdfsfiletopology.java
我对代码部分有疑问：

Yaml yaml = new Yaml();
        InputStream in = new FileInputStream(args[1]);
        Map<String, Object> yamlConf = (Map<String, Object>) yaml.load(in);
        in.close();
        config.put("hdfs.config", yamlConf);

        HdfsBolt bolt = new HdfsBolt()
                .withConfigKey("hdfs.config")
                .withFsUrl(args[0])
                .withFileNameFormat(fileNameFormat)
                .withRecordFormat(format)
                .withRotationPolicy(rotationPolicy)
                .withSyncPolicy(syncPolicy)
                .addRotationAction(new MoveFileAction().toDestination("/dest2/"));

这部分代码做什么，尤其是yaml部分？