@Test
  void urlPathConcatUrlTrailingSlash() throws Exception {
    server.enqueue(new MockResponse().setBody("response data"));

    String url = "http://localhost:" + server.getPort() + "/";
    TestInterface api = Feign.builder().target(TestInterface.class, url);

    api.codecPost("request data");
    assertThat(server.takeRequest()).hasPath("/");
  }
Shows exception handling isn't required to coerce 204 to null or empty
core/src/test/java/feign/FeignBuilderTest.java