anchor.diff:  let
     # Change this to test a different version of Cassandra:
     testPackage = pkgs.cassandra;
  -  cassandraCfg = hostname:
  +
  +  cassandraCfg = ipAddress:
       { enable = true;
  -      listenAddress = hostname;
  -      rpcAddress = hostname;
  +      listenAddress = ipAddress;
  +      rpcAddress = ipAddress;
         extraConfig =
           { start_native_transport = true;
             seed_provider =
  
positive.code:       $cass1->waitUntilSucceeds("nodetool status | egrep -c '^UN'  | grep 2");
        $cass0->succeed("nodetool status | egrep -c '^UN'  | grep 2");
      };
      subtest "replace crashed node", sub {
        $cass1->crash;
        $cass2->waitForUnit("cassandra.service");
        $cass0->waitUntilFails("nodetool status --resolve-ip | egrep '^UN[[:space:]]+cass1'");
  
negative.code:   };
  
    testScript = ''
      # Check configuration
      subtest "Timers exist", sub {
        $cass0->succeed("systemctl list-timers | grep cassandra-full-repair.timer");
        $cass0->succeed("systemctl list-timers | grep cassandra-incremental-repair.timer");
      };
      subtest "Can connect via cqlsh", sub {
        $cass0->waitForUnit("cassandra.service");
        $cass0->waitUntilSucceeds("nc -z cass0 9042");
        $cass0->succeed("echo 'show version;' | cqlsh cass0");
      };
      subtest "Nodetool is operational", sub {
        $cass0->waitForUnit("cassandra.service");
        $cass0->waitUntilSucceeds("nc -z localhost 7199");
        $cass0->succeed("nodetool status --resolve-ip | egrep '^UN[[:space:]]+cass0'");
      };
  
      # Check cluster interaction
      subtest "Bring up cluster", sub {
        $cass1->waitForUnit("cassandra.service");
        $cass1->waitUntilSucceeds("nodetool status | egrep -c '^UN' | grep 2");
        $cass0->succeed("nodetool status --resolve-ip | egrep '^UN[[:space:]]+cass1'");
      };
      subtest "Break and fix node", sub {
        $cass1->block;
        $cass0->waitUntilSucceeds("nodetool status --resolve-ip | egrep -c '^DN[[:space:]]+cass1'");
        $cass0->succeed("nodetool status | egrep -c '^UN'  | grep 1");
  