@Override
      void visitClass(Class<?> t) {
        builder.add(t);
      }

      @Override
      void visitGenericArrayType(GenericArrayType t) {
        builder.add(Types.getArrayClass(of(t.getGenericComponentType()).getRawType()));
      }
    }.visit(runtimeType);
    // Cast from ImmutableSet<Class<?>> to ImmutableSet<Class<? super T>>
    @SuppressWarnings({"unchecked", "rawtypes"})