class CreateClient implements Runnable {

    @Override
    public void run() {

        if (!force && manager.doesClientExist(firstName, lastName, dateOfBirth)) {
            outputStream.println("Duplicate client found, use --force to create anyway");
            return;
        }

        Client client = new Client(firstName, middleNames, lastName, dateOfBirth, null);

        Action action = new CreateClientAction(client, manager);

        outputStream.println(invoker.execute(action));
    }

    public  CreateClient(PrintStream outputStream, ActionInvoker invoker);
    public  CreateClient(ClientManager manager, ActionInvoker invoker);

}