anchor.diff:      //
       Expression expression = parseConditionalExpression();
       if (_currentToken.type.isAssignmentOperator) {
  -      Token operator = andAdvance;
  +      Token operator = getAndAdvance();
         _ensureAssignable(expression);
         expression = new AssignmentExpression(
             expression,
  
positive.code:     Token equals = null;
      Expression initializer = null;
      if (_matches(TokenType.EQ)) {
        equals = andAdvance;
        initializer = parseExpression2();
      }
      return new VariableDeclaration(
  
negative.code:     Expression expression;
      if (_matchesKeyword(Keyword.SUPER) &&
          _currentToken.next.type.isEqualityOperator) {
        expression = new SuperExpression(getAndAdvance());
      } else {
        expression = _parseRelationalExpression();
      }
      bool leftEqualityExpression = false;
      while (_currentToken.type.isEqualityOperator) {
        Token operator = getAndAdvance();
        if (leftEqualityExpression) {
          _reportErrorForNode(
              ParserErrorCode.EQUALITY_CANNOT_BE_EQUALITY_OPERAND,
  