docs: private String _read(String rowKey) throws RowNotFoundException {
          Row row = CqlUtils.executeOne(sessionHelper.getSession(), cqlGetMetadata,
                  ConsistencyLevel.LOCAL_ONE, rowKey);
          String jsonString = row != null ? row.getString(CqlTemplate.COL_METADATA_METADATA) : null;
          if (jsonString != null) {
              return jsonString;
          }
          throw new RowNotFoundException(rowKey);
      }