title: Rails 4, Devise remember token
body: <p>I am trying to find how <a href="https://github.com/plataformatec/devise" rel="noreferrer">devise</a> generates the <code>remember_token</code>.  </p>
  
  <p>I have noticed that it is generated (and stored in a cookie) even when there is no token column in the DB to hold it. I'd like to understand how it works, but I cannot find the right location in its source.</p>
  
  <p>Could anyone point me to the source code file, please?</p>