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:       return e.computeType(compiler);
      }
  
      var creates =
          _collect(element, compiler,
              compiler.enqueuer.resolution.nativeEnqueuer.annotationCreatesClass,
              lookup);
      var returns =
          _collect(element, compiler,
              compiler.enqueuer.resolution.nativeEnqueuer.annotationReturnsClass,
              lookup);
  
      if (creates != null) {
        typesInstantiated..clear()..addAll(creates);
  
negative.code:     super.processNativeClasses(libraries);
  
      // HACK HACK - add all the resolved classes.
      NativeEnqueuerBase enqueuer = compiler.enqueuer.resolution.nativeEnqueuer;
      for (final classElement in enqueuer.registeredClasses) {
        if (unusedClasses.contains(classElement)) {
          enqueueClass(classElement, 'was resolved');
        }
  