docs: private BaseDescr lhsEval(CEDescrBuilder<?, ?> ce) throws RecognitionException {
          EvalDescrBuilder<?> eval = null;
  
          try {
              eval = helper.start(ce,
                      EvalDescrBuilder.class,
                      null);
  
              match(input,
                      DRL6Lexer.ID,
                      DroolsSoftKeywords.EVAL,
                      null,
                      DroolsEditorType.KEYWORD);
              if (state.failed)
                  return null;
  
              if (!parseEvalExpression(eval))
                  return null;
  
          } catch (RecognitionException e) {
              throw e;
          } finally {
              helper.end(EvalDescrBuilder.class,
                      eval);
          }
  
          return eval != null ? eval.getDescr() : null;
      }