泛型的泛型数组，其中泛型是父类

Question

我遇到了一些泛型问题。

我有：

class SyncRequest<Type>: ApiRequest<Type> where Type:SyncableModel {} // really empty. Used only for tipisation

class SyncableModel: BaseModel {...} // BaseModel is class also

class SyncServiceImpl: SyncService {
    private var registeredRequests: [SyncRequest<SyncableModel>]
    init() {
        registeredRequests.append(SyncRequest<EventGroup>("{somepath}"))
    }
}

但是有一个错误说

  

＆＃34;无法转换类型＆＃39; SyncRequest＆lt; .EventGroup＆gt;＆＃39;的值预期   参数类型＆＃39; SyncRequest＆lt; .SyncableModel＆gt;＆＃39;＆＃34;

有没有办法将子类用作泛型类型？