docs: public Query adding( Column... columns ) {
          List<Column> newColumns = null;
          if (this.columns != null) {
              newColumns = new ArrayList<Column>(this.columns);
              for (Column column : columns) {
                  newColumns.add(column);
              }
          } else {
              newColumns = Arrays.asList(columns);
          }
          return new Query(source, constraint, orderings(), newColumns, getLimits(), distinct);
      }