anchor.diff:      if (_hasHiddenName) {
         Element hiddenElement = _hiddenElements[name];
         if (hiddenElement != null) {
  -        errorListener.onError(new AnalysisError.con2(getSource(identifier),
  +        errorListener.onError(new AnalysisError(getSource(identifier),
               identifier.offset, identifier.length,
               CompileTimeErrorCode.REFERENCED_BEFORE_DECLARATION, []));
           return hiddenElement;
  
positive.code:         }
          if (_findForwardedConstructors(classElement, superType, callback)) {
            if (implicitConstructors.isEmpty) {
              errorListener.onError(new AnalysisError.con2(classElement.source,
                  classElement.nameOffset, classElement.name.length,
                  CompileTimeErrorCode.MIXIN_HAS_NO_CONSTRUCTORS,
                  [superElement.name]));
  
negative.code:   Source getSource(UriBasedDirective directive) {
      StringLiteral uriLiteral = directive.uri;
      if (uriLiteral is StringInterpolation) {
        _errorListener.onError(new AnalysisError(librarySource, uriLiteral.offset,
            uriLiteral.length, CompileTimeErrorCode.URI_WITH_INTERPOLATION));
        return null;
      }
      String uriContent = uriLiteral.stringValue.trim();
  