anchor.diff:    testScript = ''
       client.wait_for_unit("dnsmasq")
       client.wait_for_unit("dnscrypt-proxy2")
  +    client.wait_until_succeeds("ss --numeric --udp --listening | grep -q ${toString localProxyPort}")
     '';
   })
  
positive.code:     # for a caching DNS client.
      client =
      { ... }:
      let localProxyPort = 43; in
      {
        security.apparmor.enable = true;
  
  
negative.code: import ./make-test-python.nix ({ pkgs, ... }: let
    localProxyPort = 43;
  in {
    name = "dnscrypt-proxy2";
    meta = with pkgs.lib.maintainers; {
      maintainers = [ joachifm ];
  