join

 // Create dataSet
 DataSet dataSet = new DataSet();

 // Load dataSet with information
 for (i = 0; i < 3; ++i)
 {
     DataRecord record = new DataRecord();
     record.put("DATA_SET_ONE", i);
     dataSet.addDataRecord(record);
 }

 // Create another dataSet
 DataSet anotherDataSet = new DataSet();

 // Load dataSet with information
 for (i = 0; i < 2; ++i)
 {
     DataRecord record = new DataRecord();
     record.put("DATA_SET_TWO", i);
     anotherDataSet.addDataRecord(record);
 }

 // Join DataSets
 dataSet.join(anotherDataSet);

 // Write merged DataSet to Log (in dataRecords)
 for (i = 0; i < dataSet.getNumDataRecords(); ++i)
 {
     DataRecord record = dataSet.getDataRecord(i);
     session.log("DataRecord " + i + ": " + record.toString());
 }

 // Log Output:
 // DataRecord 0: {DATA_SET_TWO=0, DATA_SET_ONE=0}
 // DataRecord 1: {DATA_SET_TWO=1, DATA_SET_ONE=1}
 // DataRecord 2: {DATA_SET_ONE=2}