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

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

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