### Question:
IpBlockInterceptor implements ServerInterceptor { public void setBlackIps(String[] ips) { this.blackIps = ips; this.blackIpsForLog = Arrays.toString(blackIps); }  void setBlackIps(String[] ips); @Override ServerCall.Listener<ReqT> interceptCall(
            ServerCall<ReqT, RespT> call, Metadata headers, ServerCallHandler<ReqT, RespT> next);  }### Answer:
@Test(expected = StatusRuntimeException.class) public void testIpBlockInterceptor() { assertThat(grpcServerRunner).isNotNull(); ManagedChannel channel = ManagedChannelBuilder .forAddress("localhost", runningPort) .usePlaintext().build(); Proto.Pong reply = DiscoveryServiceGrpc.newBlockingStub(channel) .ping(Proto.Ping.newBuilder().setPing("Ping").build()); reply.getPong(); assertThat(reply.getPong()).isEqualTo("Pong"); ((IpBlockInterceptor) ipBlockInterceptor).setBlackIps(new String[] {"127.0.0.1"}); DiscoveryServiceGrpc.newBlockingStub(channel).ping(Proto.Ping.newBuilder().setPing("Ping").build()); }