Kotlin数据类中模型继承的改进与接口

我有一个get请求,它返回某些特性,其中对象的11个属性是公共的。由于Kotlin中的数据类不能从其他类继承,我决定用下面的接口定义公共属性。

interface AccountFeature {
    val feature: String?
    val status: String?
    val id: String?
    val urlLogo: String?
    val minAppVersion: String?
    val target: String?
    val title: String?
    val backgroundColor: String?
    val bodyTextColor: String?
    val bodyText: String?
    val titleTextColor: String?
}

其中一个数据类如下所示。

data class AccountFeatureHelp(val privacyStatement: String? = null,
                              val supportFAQ: String? = null,
                              val termsOfService: String? = null,
                              val supportHotline: String? = null,
                              val supportEmail: String? = null,
                              override val feature: String?,
                              override val status: String?,
                              override val id: String?,
                              override val urlLogo: String?,
                              override val minAppVersion: String?,
                              override val target: String?,
                              override val title: String?,
                              override val backgroundColor: String?,
                              override val bodyTextColor: String?,
                              override val bodyText: String?,
                              override val titleTextColor: String?): AccountFeature

到目前为止一切都很好。

在我的请求的接口定义中,我期望一个AccountFeature的可观察数组。我的目标是根据特性值,将hashmap映射到相应的feature对象。

interface  AccountFeaturesAPIService {
    @GET("accounts/{id}/features")
    fun getAccountFeature(@Path("id") id: String): Observable<Array<AccountFeature>>
}

我得到以下运行时异常。

java.lang.RuntimeException: Unable to invoke no-args constructor for interface com.thinxnet.native_tanktaler_android.core.model.account.feature.AccountFeature. Registering an InstanceCreator with Gson for this type may fix this problem.

除了将Observable>改为Observable>之外,我如何优雅地克服这一点;