@Test
  void customExpanderListParam() throws Exception {
    server.enqueue(new MockResponse());

    final TestInterfaceAsync api =
        new TestInterfaceAsyncBuilder().target("http://localhost:" + server.getPort());

    final CompletableFuture<?> cf =
        api.expandList(Arrays.asList(new TestClock(1234l), new TestClock(12345l)));

    assertThat(server.takeRequest()).hasPath("/?clock=1234&clock=12345");

    checkCFCompletedSoon(cf);
  }
The type of a parameter value may not be the desired type to encode as. Prefer the interface
type.
hc5/src/test/java/feign/hc5/AsyncApacheHttp5ClientTest.java