code: @Setup
    @SuppressWarnings({"unchecked", "rawtypes"})
    public void setUp() {
      serverToRemove = create();
      channelz.addServer(serverToRemove);
  
      serverForServerSocket = create();
      channelz.addServer(serverForServerSocket);
  
      serverSocketToRemove = create();
      channelz.addClientSocket(serverSocketToRemove);
      channelz.addServerSocket(serverForServerSocket, serverSocketToRemove);
  
      populate(preexisting);
  
      serverToAdd = create();
      serverSocketToAdd = create();
    }
docs: Javadoc.