structuralSchemaGK:    kind.GroupKind(),
			preserveUnknownFields: crd.Spec.PreserveUnknownFields,
			supportedMediaTypes: []runtime.SerializerInfo{
				{
					MediaType:        "application/json",
					MediaTypeType:    "application",
					MediaTypeSubType: "json",
					EncodesAsText:    true,
					Serializer:       json.NewSerializer(json.DefaultMetaFactory, creator, typer, false),

	for _, s := range a.group.Serializer.SupportedMediaTypes() {
		if len(s.MediaTypeSubType) == 0 || len(s.MediaTypeType) == 0 {
			return nil, nil, fmt.Errorf("all serializers in the group Serializer must have MediaTypeType and MediaTypeSubType set: %s", s.MediaType)
		}
	}
	mediaTypes, streamMediaTypes := negotiation.MediaTypesForSerializer(a.group.Serializer)