class HtmlSettingsConverter : Converter.Factory() {

    override fun responseBodyConverter(
        type: Type,
        annotations: Array<Annotation>,
        retrofit: Retrofit
    ): Converter<ResponseBody, *> {
        if (type is LinkedInUserSettings) // Error here
            return HtmlConverter.INSTANCE
        else
            return null
    }

    class HtmlConverter : Converter<ResponseBody, UserSettings> {

    }
}