anchor.diff:                        [{dbdir, "dbdir"},
                          {bucket_engine, "old-be"},
                          {engines, "old-engines"}]},
  -                     {port_servers,
  +                     {{node, node(), port_servers},
                         [{moxi, "moxi old something"},
                          {memcached, "memcached old something"}]},
                        {{node, node(), ns_log}, default_log}]],
  
positive.code:                   {{node, node(), memcached},
                     [{bucket_engine, "new-be"},
                      {engines, "new-engines"}]},
                    {port_servers,
                     [{moxi, "moxi something"},
                      {memcached, "memcached something"}]},
                    {{node, node(), ns_log}, default_log}],
  
negative.code:                               [{dbdir, "dbdir"},
                                 {bucket_engine, "new-be"},
                                 {engines, "new-engines"}]},
                               {set, {node, node(), port_servers},
                                [{moxi, "moxi something"},
                                 {memcached, "memcached something"}]},
                               {set, {node, node(), ns_log}, default_log}]),
  