anchor.diff:      
       _currentDelimiters = _delimiters;
       
  +    _stack.clear();
       _stack.add(new SectionNode('root', 0, 0, _delimiters));    
     
       // Handle standalone tag on first line.
  
positive.code:     return token;
    }
    
    Token _readIf(TokenType type) {
      var token = _peek();
      if (token == null) throw 'End of file!'; //TODO error message.
      return token.type == type ? _read() : null;
    }
    
    // Add a text node to top most section on the stack and merge consecutive
  
negative.code:     
        assert(_peek().type == TokenType.lineEnd || _i == 0);
    
        var precedingLineEnd = _readIf(TokenType.lineEnd, eofOk: true);
        var precedingWhitespace = _readIf(TokenType.whitespace, eofOk: true);
            
        Tag tag;
        Node tagNode;
  