@Override
  public RecordReader<LongWritable, WARCWritable> createRecordReader(InputSplit split,
    TaskAttemptContext context) throws IOException, InterruptedException {
    return new WARCReader();
  }
Opens a WARC file (possibly compressed) for reading, and returns a RecordReader for accessing
it.
hbase-it/src/test/java/org/apache/hadoop/hbase/test/util/warc/WARCInputFormat.java