@Test void newBuilderWithPort_tooHighIsInvalid() {
    Throwable exception = assertThrows(IllegalArgumentException.class, () -> {
      Endpoint.newBuilder().port(65536).build();
    });
    assertThat(exception.getMessage()).contains("invalid port 65536");
  }
The integer arg of port should fit in a 16bit unsigned value
zipkin/src/test/java/zipkin2/EndpointTest.java