code: public TableIdx getTableIdx(final String _tableName,
                                  final String... _keys)
      {
          TableIdx ret = null;
          final String key = _tableName + "-" + StringUtils.join(_keys, "-");
          final Optional<TableIdx> val = this.tableidxs.stream().filter(t -> t.getKey().equals(key)).findFirst();
          if (val.isPresent()) {
              ret = val.get();
              ret.setCreated(false);
          } else {
              ret = new TableIdx().setCreated(true).setTable(_tableName).setIdx(this.currentIdx++).setKey(key);
              this.tableidxs.add(ret);
          }
          return ret;
      }
docs: Gets the table idx.
  
  @param _tableName the table name
  @param _keys the key
  @return the table idx