�供<code>XxxxPowerApi</code>结尾的服务接口。</p>
<pre class="prettyprint"><code class="language-scala">trait GreeterServicePowerApi extends GreeterService {
  
  def sayHello(
    in: greeter.HelloRequest,
    metadata: Metadata): scala.concurrent.Future[greeter.HelloReply]
  
  def itKeepsTalking(
    in: akka.stream.scaladsl.Source[greeter.HelloRequest, akka.NotUsed],
    metadata: Metadata): scala.concurrent.Future[greeter.HelloReply]
  
  def itKeepsReplying(
    in: greeter.HelloRequest,
    m