if (args == null || args.getTail() != null)
{
return null;
}
AggregateOperator op = create(query);
if (!op.setOperand(query.createOperator(
(op instanceof UniqueOperator || query.isGroupedBy() || query.isAggregate()) ? key : op, args.getHead(),
(nOutput == OUTPUT_UNKNOWN) ? OUTPUT_UNKNOWN : OUTPUT_NONE)))
{
return null;
}