anchor.diff:               upgrade_config_from_2_2_0_to_2_3_0(Config)];
           {value, {2,3,0}} ->
               [{set, {node, node(), config_version}, {3,0}} |
  -             upgrade_config_from_2_3_0_to_3_0(Config)]
  +             upgrade_config_from_2_3_0_to_3_0(Config)];
  +        {value, {3,0}} ->
  +            [{set, {node, node(), config_version}, {3,0,1}} |
  +             upgrade_config_from_3_0_to_3_0_1(Config)]
       end.
   
   upgrade_config_from_1_7_to_1_7_1() ->
  
positive.code: -define(NS_LOG, "ns_log").
  
  get_current_version() ->
      {3,0}.
  
  % Allow all keys to be mergable.
  
  
negative.code:                   {set, {node, _, memcached_config}, _}],
                   do_upgrade_config_from_2_3_0_to_3_0(Cfg, Default)).
  
  upgrade_3_0_to_3_0_1_test() ->
      Cfg = [[{some_key, some_value},
              {{node, node(), memcached},
               [{engines, old_value},
                {ssl_port, 1},
                {verbosity, 2},
                {port, 3}]},
              {{node, node(), memcached_config}, memcached_config}]],
      Default = [{{node, node(), port_servers}, port_servers_cfg},
                 {{node, node(), memcached}, [{ssl_port, 1}, {verbosity, 3},
                                              {engines, [something]}]},
                 {{node, node(), memcached_config}, memcached_config}],
  
      ?assertMatch([{set, {node, _, memcached}, [{engines, [something]},
                                                 {ssl_port, 1}, {verbosity, 2},
                                                 {port, 3}]}],
                   do_upgrade_config_from_3_0_to_3_0_1(Cfg, Default)).
  
  
  no_upgrade_on_current_version_test() ->
      ?assertEqual([], upgrade_config([[{{node, node(), config_version}, get_current_version()}]])).
  
  