@Override
public Operator createOperator(DriverContext driverContext)
{
OperatorContext operatorContext = driverContext.addOperatorContext(operatorId, MaterializingOperator.class.getSimpleName());
MaterializingOperator operator = new MaterializingOperator(operatorContext, sourceTupleInfo);
if (!materializingOperator.compareAndSet(null, operator)) {
throw new IllegalArgumentException("Output already created");
}
return operator;