anchor.diff:                     {servers, Servers},
                      {clients, Clients}]),
   
  -    %% Pause for clustering.
  -    timer:sleep(1000),
  +    ?PAUSE_FOR_CLUSTERING,
   
       %% Test on_down callback.
       [{_, _}, {_, _}, {_, Node3}, {_, Node4}] = Nodes,
  
positive.code:                    {servers, Servers},
                     {clients, Clients}]),
  
      %% Pause for clustering.
      timer:sleep(1000),
  
      %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
      %% gen_server tests.
  
negative.code: 
      %% Ensure that a regular call works.
      [{_, FirstName}, {_, SecondName} | _] = Nodes,
  
      ok = rpc:call(
          FirstName,
          partisan_gen_server, call,
          [{partisan_test_server, SecondName}, call, 5000]
      ),
  
      %% Ensure that a regular call with delayed response works.
      [{_, FirstName}, {_, SecondName} | _] = Nodes,
  
      ok = rpc:call(
          FirstName,
          partisan_gen_server,
          call,
          [{partisan_test_server, SecondName}, delayed_reply_call, 5000]
      ),
  
      %% Ensure that a cast works.
      Self = self(),
  