docs: public AggregationBuilder makeFieldAgg(MethodField field, AggregationBuilder parent) throws SqlParseException {
          //question 加到groupMap里是为了什么
          groupMap.put(field.getAlias(), new KVValue("FIELD", parent));
  
          ValuesSourceAggregationBuilder builder;
          field.setAlias(fixAlias(field.getAlias()));
          switch (field.getName().toUpperCase()) {
              case "SUM":
                  builder = AggregationBuilders.sum(field.getAlias());
                  return addFieldToAgg(field, builder);
              case "MAX":
                  builder = AggregationBuilders.max(field.getAlias());
                  return addFieldToAgg(field, builder);
              case "MIN":
                  builder = AggregationBuilders.min(field.getAlias());
                  return addFieldToAgg(field, builder);
              case "AVG":
                  builder = AggregationBuilders.avg(field.getAlias());
                  return addFieldToAgg(field, builder);
              case "STATS":
                  builder = AggregationBuilders.stats(field.getAlias());
                  return addFieldToAgg(field, builder);
              case "EXTENDED_STATS":
                  builder = AggregationBuilders.extendedStats(field.getAlias());
                  return addFieldToAgg(field, builder);
              case "PERCENTILES":
                  builder = AggregationBuilders.percentiles(field.getAlias());
                  addSpecificPercentiles((PercentilesAggregationBuilder) builder, field.getParams());
                  return addFieldToAgg(field, builder);
              case "TOPHITS":
                  return makeTopHitsAgg(field);
              case "SCRIPTED_METRIC":
                  return scriptedMetric(field);
              case "COUNT":
                  groupMap.put(field.getAlias(), new KVValue("COUNT", parent));
                  return addFieldToAgg(field, makeCountAgg(field));
              default:
                  throw new SqlParseException("the agg function not to define !");
          }
      }