anchor.diff:  }
   
   
  -class NativeEnqueuerBase implements NativeEnqueuer {
  +abstract class NativeEnqueuerBase implements NativeEnqueuer {
   
     /**
      * The set of all native classes.  Each native class is in [nativeClasses] and
  
positive.code:     super.processNativeClasses(libraries);
  
      // HACK HACK - add all the resolved classes.
      for (final classElement
           in compiler.enqueuer.resolution.nativeEnqueuer.registeredClasses) {
        if (unusedClasses.contains(classElement)) {
          enqueueClass(classElement, 'was resolved');
        }
  
negative.code:       var fields = value.fields;
        // TODO(sra): Better validation of the constant.
        if (fields.length != 1 || fields[0] is! StringConstant) {
          PartialMetadataAnnotation partial = annotation;
          compiler.cancel(
              'Annotations needs one string: ${partial.parseNode(compiler)}');
        }
        String specString = fields[0].toDartString().slowToString();
        for (final typeString in specString.split('|')) {
  