def load(key, options = {})
      @stack.each do |s|
        value = s.load(key, options)
        return value if value != nil
      end
      nil
    end
def load(key, options = {})
      @stack.each do |s|
        value = s.load(key, options)
        return value if value != nil
      end
      nil
    end
(see Proxy#load)