protected boolean doProcess(Record inputRecord) {
Record outputRecord = inputRecord.copy();
// change key
Text myTextKey = (Text)inputRecord.getFirstValue(this.keyField);
outputRecord.replaceValues(this.keyField, MyWritable.keyStr(myTextKey));
// change value
MyWritable myWritableValue = (MyWritable)inputRecord.getFirstValue(this.valueField);
outputRecord.replaceValues(this.valueField, MyWritable.valueStr(myWritableValue));
return super.doProcess(outputRecord);
}