def inheritable_cache #:nodoc:
      # do not store keys on each access, only return default structure
      @inheritable_cache ||= Hash.new do |h1, k1| 
        Hash.new do |h2, k2| 
          Hash.new do |h3, k3| 
            Hash.new 
          end
        end
      end
    end
def inheritable_cache #:nodoc:
      # do not store keys on each access, only return default structure
      @inheritable_cache ||= Hash.new do |h1, k1| 
        Hash.new do |h2, k2| 
          Hash.new do |h3, k3| 
            Hash.new 
          end
        end
      end
    end
A simple template lookup cache for each controller.