@Override
    public void map(WritableComparable key, HCatRecord value, Context context)
        throws IOException, InterruptedException {
      try {
        readRecords.add(value);
        readCount++;
      } catch (Exception e) {
        // Print since otherwise exception is lost.
        e.printStackTrace();
        throw new IOException(e);
      }
    }
Test constructor that sets the storage format class names provided by the test parameter.
hcatalog/core/src/test/java/org/apache/hive/hcatalog/mapreduce/HCatMapReduceTest.java