anchor.diff:                                                    "vbucket map chain: ~p", [NodeIx]),
                                 ?log_error("~s", [Msg]),
                                 {error, bad_value, iolist_to_binary(Msg)};
  +                          {ok, none} ->
  +                              Msg = io_lib:format("Invalid node reference in "
  +                                                  "vbucket map chain: ~p. "
  +                                                  "Found node without couchApiBase in active vbucket map position", [NodeIx]),
  +                              ?log_error("~s", [Msg]),
  +                              {error, bad_value, iolist_to_binary(Msg)};
                             {ok, URL} ->
                                 VBucketURL0 = [URL, "%2f", integer_to_list(VBucket),
                                                "%3b", BucketUUID],
                                 VBucketURL = iolist_to_binary(VBucketURL0),
  -                              do_build_vbmap_chain(Rest, BucketUUID, IxToCouchDict,
  -                                                   VBucket, [VBucketURL | R])
  +                              {ok, [VBucketURL]}
                         end
                 end
         end).
  
positive.code:       end).
  
  build_vbmap_chain(Chain, BucketUUID, IxToCouchDict, VBucket) ->
      do_build_vbmap_chain(Chain, BucketUUID, IxToCouchDict, VBucket, []).
  
  do_build_vbmap_chain([], _, _, _, R) ->
      {ok, lists:reverse(R)};
  do_build_vbmap_chain([NodeIxRaw | Rest], BucketUUID, IxToCouchDict, VBucket, R) ->
      expect_number(
        NodeIxRaw, <<"Vbucket map chain">>,
        fun (NodeIx) ->
                case NodeIx of
                    -1 ->
                        do_build_vbmap_chain(Rest, BucketUUID, IxToCouchDict,
                                             VBucket, [undefined | R]);
                    _ ->
                        case dict:find(NodeIx, IxToCouchDict) of
                            error ->
  
negative.code:     do_build_ix_to_couch_uri_dict(ServerList, McdToCouchDict, 0, dict:new()).
  
  do_build_ix_to_couch_uri_dict([], _McdToCouchDict, _Ix, D) ->
      D;
  do_build_ix_to_couch_uri_dict([S | Rest], McdToCouchDict, Ix, D) ->
      case dict:find(S, McdToCouchDict) of
          error ->
              ?log_debug("Was not able to find node corresponding to server ~s. Assuming it's couchApiBase-less node", [S]),
  
              D1 = disc:store(Ix, none, D),
              do_build_ix_to_couch_uri_dict(Rest, McdToCouchDict, Ix + 1, D1);
          {ok, Value} ->
              D1 = dict:store(Ix, Value, D),
              do_build_ix_to_couch_uri_dict(Rest, McdToCouchDict, Ix + 1, D1)
  