"type": "keyword"
        },
        "match": "*",
        "match_mapping_type": "string"
      }
    }
  ],
  "properties": {
    "@timestamp": {
      "type": "date",
      "format": "epoch_millis"
    },
    "docFreq": {
      "type": "long"
    },
    "fields": {
      "type": "keyword"
    },
    "kinds": {
      "type": "keyword"
    },
    "queryFreq": {
      "type": "long"

            throw new IllegalArgumentException(msg);
        }
    }

    protected String toRangeDateString(Date date, String format) {
        if (format.contains("epoch_millis")) {
            return Long.toString(date.getTime());
        } else if (format.contains("date_optional_time")) {
            final SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");

            throw new IllegalArgumentException(msg);
        }
    }

    protected String toRangeDateString(Date date, String format) {
        if (format.contains("epoch_millis")) {
            return Long.toString(date.getTime());
        } else if (format.contains("date_optional_time")) {
            final SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");

            throw new IllegalArgumentException(msg);
        }
    }

    protected String toRangeDateString(Date date, String format) {
        if (format.contains("epoch_millis")) {
            return Long.toString(date.getTime());
        } else if (format.contains("date_optional_time")) {
            final SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");