I'll save new content programmatically and I use this code:

private void CreateSubscription(string fullname, string company, string email, int eventId)
{
    ContentService cs = new ContentService(); // <-- on this line
    var content = cs.CreateContent(_rnd.Next().ToString(), eventId, "subscription");
    content.SetValue("fullname", fullname);
    content.SetValue("email", email);
    content.SetValue("company", company);

    cs.Save(content);
}

I've taken it from here: Replay on Create new content nodes programmatically.

But this gives me this error on the marked line:

There is no argument given that corresponds to the required formal parameter provider of ContentService.ContentService(IDatabaseUnitOfWorkProvider, RepositoryFactory, ILogger, IEventMessagesFactory, IDataTypeService, IUserService)

What do I wrong? I'm using Umbraco 7.7.