HTTP Header）的访问接口。</p>
<p>通过Akka gRPC生成的服务句柄类（<code>GreeterServicePowerApiHandler</code>），可以清晰的知道Akka gRPC是怎么创建<code>Metadata</code>的。</p>
<pre class="prettyprint"><code class="language-scala">def partial(
    implementation: GreeterServicePowerApi,
    prefix: String = GreeterService.name,
    eHandler: ActorSystem =&gt; PartialFunction[Throwable, io.grpc.Status] = GrpcExceptionHandler.defaultMapper
  )(implicit mat: Materializer, system: 