# File lib/gibbler.rb, line 453
    def __gibbler(digest_type=nil)
      klass = self.class
      d, index = [], 0
      self.each_with_index do |value,idx| 
        unless value.respond_to? :__gibbler
          gibbler_debug klass, :skipping, idx
          next
        end
        d << '%s:%s:%s' % [value.class, index, value.__gibbler(digest_type)]
        index += 1
      end
      d = d.join(':').__gibbler(digest_type)
      a = Gibbler.digest '%s:%s:%s' % [klass, d.size, d], digest_type
      gibbler_debug klass, a, [klass, d.size, d]
      a
    end