docs: private void contains(boolean own) {
          tq.consume(own ? ":containsOwn" : ":contains");
          String searchText = TokenQueue.unescape(tq.chompBalanced('(', ')'));
          Validate.notEmpty(searchText, ":contains(text) query must not be empty");
          if (own)
              evals.add(new Evaluator.ContainsOwnText(searchText));
          else
              evals.add(new Evaluator.ContainsText(searchText));
      }