code: private void parseRangeExpr() throws TTXPathException {
  
          parseAdditiveExpr();
          if (is("to", true)) {
  
              mPipeBuilder.addExpressionSingle();
  
              parseAdditiveExpr();
              mPipeBuilder.addRangeExpr(getTransaction());
  
          }
      }
docs: Parses the the rule RangeExpr according to the following production rule:
  <p>
  [11] RangeExpr ::= AdditiveExpr ( "to" AdditiveExpr )? .
  </p>
  
  @throws TTXPathException