@Override
        public RelNode visit(SetQueryOperation setOperation) {
            switch (setOperation.getType()) {
                case INTERSECT:
                    relBuilder.intersect(setOperation.isAll());
                    break;
                case MINUS:
                    relBuilder.minus(setOperation.isAll());
                    break;
                case UNION:
                    relBuilder.union(setOperation.isAll());
                    break;
            }
            return relBuilder.build();
        }
Get the {@link AggCall} correspond to the aggregate or table aggregate expression.
core/src/main/java/org/apache/flink/table/planner/plan/QueryOperationConverter.java