试图创建一个＆＃34;提供商＆＃34;在scala中使用泛型

Question

我正在尝试在scala中创建一个提供程序类，它将在调用时返回正确的对象

性状

trait RemoteValidator[A <:Widget]{
def processRemoteValidation(request: EventRequest[_], widget: A):     Future[Seq[Widget]]
}

类扩展特性

class ResourceInstanceListRemoteValidator @Inject() extends RemoteValidator[InstanceListWidget[InstanceWidget]] {

  override def processRemoteValidation(request: EventRequest[_], widget: InstanceListWidget[InstanceWidget]): Future[Seq[Widget]] = {
     //stuff
  }

提供商

class RemoteValidatorProvider[T] @Inject()(resourceInstanceListRemoteValidator: ResourceInstanceListRemoteValidator) {
 val validators = Map("resources" -> resourceInstanceListRemoteValidator)
 def getRemoteValidator(key: String): Option[RemoteValidator] = {
 validators.get(key)
 }
}

issuse是当我调用provider.processRemoteValidation（request，instanceListWidget）时，我得到＆＃34;类型不匹配期望类型A，实际InstanceListWidget [InstanceWidget]。我知道这可以在java中工作，但是我不太熟悉scala中的泛型，我该怎么做呢？