public static <Req extends RpcRequest> Matcher<Req> serviceEquals(String service) {
    if (service == null) throw new NullPointerException("service == null");
    if (service.isEmpty()) throw new NullPointerException("service is empty");
    return new RpcServiceEquals<Req>(service);
  }
@Test void serviceEquals_unmatched_mixedCase() {
    when(request.service()).thenReturn("grpc.health.v1.Health");

    assertThat(serviceEquals("grpc.health.v1.health").matches(request)).isFalse();
  }