$jruby_shared_map.put_if_absent('rule_sets', Hash.new { |hash, key| puts "Creating new RuleSet: #{key}"; hash[key]= RuleSet.new })
            rule_set_map = $jruby_shared_map.get('rule_sets')
            rule_context = name ? rule_set_map[name] : RuleSet.new
            rule_context.instance_eval(&block