code: @Override
      public Map<String, Object> toSource() {
          Map<String, Object> sourceMap = new HashMap<>();
          if (createdAt != null) {
              addFieldToSource(sourceMap, "createdAt", createdAt);
          }
          if (docId != null) {
              addFieldToSource(sourceMap, "docId", docId);
          }
          if (queryId != null) {
              addFieldToSource(sourceMap, "queryId", queryId);
          }
          if (url != null) {
              addFieldToSource(sourceMap, "url", url);
          }
          if (userInfoId != null) {
              addFieldToSource(sourceMap, "userInfoId", userInfoId);
          }
          return sourceMap;
      }
docs: ======