def let(clearance_level, actions, resource, options = {})
      clearance_level = clearance_level.to_s.singularize.to_sym
      actions = Array(actions).map(&:to_sym)
      controller = get_controller_name(resource, options)
      @rules[controller] ||= {}
      @rules[controller][clearance_level] ||= []
      @rules[controller][clearance_level] += actions
      @rules[controller][clearance_level].uniq!
      return nil
    end
def let(clearance_level, actions, resource, options = {})
      clearance_level = clearance_level.to_s.singularize.to_sym
      actions = Array(actions).map(&:to_sym)
      controller = get_controller_name(resource, options)
      @rules[controller] ||= {}
      @rules[controller][clearance_level] ||= []
      @rules[controller][clearance_level] += actions
      @rules[controller][clearance_level].uniq!
      return nil
    end
Set clearance to perform actions over a resource.
 Clearance level and resource can be either plural or singular.

 == Examples:

   let :user, :show, :profile
   let :user, :show, @profile
   let :user, :show, ProfilesController
   # Any user can can access 'profiles#show'.

   let :admins, [:edit, :update], :articles, namespace: :admin
   let :admins, [:edit, :update], @admin_article
   let :admins, [:edit, :update], Admin::ArticlesController
   # Admins can access 'admin/articles#edit' and 'admin/articles#update'.