anchor.diff:  import 'package:analyzer/src/dart/resolver/scope.dart';
   import 'package:analyzer/src/dart/resolver/type_property_resolver.dart';
   import 'package:analyzer/src/error/codes.dart';
  -import 'package:analyzer/src/generated/engine.dart';
   import 'package:analyzer/src/generated/migratable_ast_info_provider.dart';
   import 'package:analyzer/src/generated/resolver.dart';
   import 'package:analyzer/src/generated/super_context.dart';
  
positive.code:       }
      } else if (identifier is PrefixedIdentifier) {
        SimpleIdentifier prefix = identifier.prefix;
        SimpleIdentifier name = identifier.identifier;
        Element element = _resolveSimpleIdentifier(prefix);
        if (element == null) {
  //        resolver.reportError(CompileTimeErrorCode.UNDEFINED_IDENTIFIER, prefix, prefix.getName());
        } else {
          prefix.staticElement = element;
          if (element is PrefixElement) {
            // TODO(brianwilkerson) Report this error?
            element = _resolver.nameScope.lookupIdentifier(identifier);
            name.staticElement = element;
            return;
          }
          LibraryElement library = element.library;
          if (library == null) {
            // TODO(brianwilkerson) We need to understand how the library could
            // ever be null.
            AnalysisEngine.instance.instrumentationService
                .logError("Found element with null library: ${element.name}");
          } else if (library != _definingLibrary) {
            // TODO(brianwilkerson) Report this error.
          }
          if (node.newKeyword == null) {
            if (element is ClassElement) {
              name.staticElement = element.getMethod(name.name) ??
                  element.getGetter(name.name) ??
                  element.getSetter(name.name) ??
                  element.getNamedConstructor(name.name);
            } else {
              // TODO(brianwilkerson) Report this error.
            }
          } else {
            if (element is ClassElement) {
              ConstructorElement constructor =
                  element.getNamedConstructor(name.name);
              if (constructor == null) {
                // TODO(brianwilkerson) Report this error.
              } else {
                name.staticElement = constructor;
              }
            } else {
              // TODO(brianwilkerson) Report this error.
            }
          }
        }
      }
    }
  
negative.code:     //
      Element prefixElement = prefix.staticElement;
      if (prefixElement is PrefixElement) {
        var lookupResult = prefixElement.scope.lookup2(identifier.name);
        var element = lookupResult.getter;
        if (element == null && identifier.inSetterContext()) {
          element = lookupResult.setter;
        }
        element = _resolver.toLegacyElement(element);
        if (element == null && _resolver.nameScope.shouldIgnoreUndefined(node)) {
  