code: public <T, K> T get(ColumnFamily<K, String> columnFamily, K id,
              Class<T> itemClass) throws Exception {
          Mapping<T> mapping = getMapping(itemClass);
          ColumnList<String> result = keyspace.prepareQuery(columnFamily)
                  .getKey(id).execute().getResult();
          return mapping.newInstance(result);
      }
docs: Get the specified item by its key/id
  
  @param columnFamily
  column family of the item
  @param id
  id/key of the item
  @param itemClass
  item's class
  @return new instance with the item's columns propagated
  @throws Exception
  errors