anchor.diff:              astFactory.constructorName(typeName, null, null);
           InstanceCreationExpression instanceCreationExpression =
               astFactory.instanceCreationExpression(
  -                _getKeyword(node), constructorName, node.argumentList);
  +                null, constructorName, node.argumentList);
           NodeReplacer.replace(node, instanceCreationExpression);
         } else if (element is ExtensionElement) {
           ExtensionOverride extensionOverride = astFactory.extensionOverride(
  
positive.code:               astFactory.constructorName(typeName, null, null);
            InstanceCreationExpression instanceCreationExpression =
                astFactory.instanceCreationExpression(
                    _getKeyword(node), constructorName, node.argumentList);
            NodeReplacer.replace(node, instanceCreationExpression);
          } else if (prefixedElement is ExtensionElement) {
            PrefixedIdentifier extensionName =
  
negative.code:       Source source,
        TypeProvider typeProvider,
        AnalysisErrorListener errorListener,
        {Scope nameScope})
        : super(definingLibrary, source, typeProvider, errorListener,
              nameScope: nameScope);
  
  