def current_user
      if (user_id = session[:user_id])
        @current_user ||= User.find_by(id: user_id)
      elsif (user_id = cookies.signed[:user_id])
        user = User.find_by(id: user_id)
        if user && user.authenticated?(cookies[:remember_token])
          log_in user
          @current_user = user
        end
      end
    end
def current_user
      if (user_id = session[:user_id])
        @current_user ||= User.find_by(id: user_id)
      elsif (user_id = cookies.signed[:user_id])
        user = User.find_by(id: user_id)
        if user && user.authenticated?(cookies[:remember_token])
          log_in user
          @current_user = user
        end
      end
    end
Returns the user corresponding to the remember token cookie.