code: @Override public RecordReader<LongWritable,SAMRecordWritable>
  		createRecordReader(InputSplit split, TaskAttemptContext ctx)
  			throws InterruptedException, IOException
  	{
  		final RecordReader<LongWritable,SAMRecordWritable> rr =
  			new SAMRecordReader();
  		rr.initialize(split, ctx);
  		return rr;
  	}
docs: Returns a {@link SAMRecordReader} initialized with the parameters.