@Override
    public int read() throws IOException {
      int result = in.read();
      if (result != -1) {
        bytesRead++;
      }
      return result;
    }
Returns the proportion of the file that has been read, as a number between 0.0 and 1.0.
hbase-it/src/test/java/org/apache/hadoop/hbase/test/util/warc/WARCFileReader.java