@Override
                                       public void applyRequestMetadata(RequestInfo requestInfo,
                                                                        Executor appExecutor,
                                                                        MetadataApplier applier) {
                                           assertThat(requestInfo.getAuthority())
                                                   .isEqualTo("127.0.0.1:" + server.httpsPort());
                                           assertThat(requestInfo.getSecurityLevel())
                                                   .isEqualTo(SecurityLevel.PRIVACY_AND_INTEGRITY);
                                           applier.apply(new Metadata());
                                       }
Must be at least {@link #unaryPayloadLength()}, plus some to account for encoding overhead.
grpc/src/test/java/com/linecorp/armeria/client/grpc/GrpcClientTest.java