docs: @Override
      public String readSingle(String key) throws Exception {
  
          ColumnList<Integer> result = keyspace.prepareQuery(this.CF)
                  .setConsistencyLevel(ConsistencyLevel.valueOf(config.getReadConsistencyLevel()))
                  .getRow(key)
                  .execute().getResult();
  
          if (!result.isEmpty()) {
              if (result.size() < (config.getColsPerRow())) {
                  throw new Exception("Num Cols returned not ok " + result.size());
              }
          } else {
              return CacheMiss;
          }
  
          return ResultOK;
      }