@Test
  void canCreateWithImplicitOrNoCredentials() throws Exception {
    Proxied proxied =
        new Proxied(TrustingSSLSocketFactory.get(), null, new Proxy(Proxy.Type.HTTP, proxyAddress));
    assertThat(proxied).isNotNull();
    assertThat(proxied.getCredentials()).isNullOrEmpty();

    /* verify that the proxy */
    HttpURLConnection connection =
        proxied.getConnection(URI.create("http://www.example.com").toURL());
    assertThat(connection).isNotNull().isInstanceOf(HttpURLConnection.class);
  }
Test that the proxy is being used, but don't check the credentials. Credentials can still be
used, but they must be set using the appropriate system properties and testing that is not what
we are looking to do here.
core/src/test/java/feign/client/DefaultClientTest.java