anchor.diff:  
   -spec split_host_port(list(), list()) -> tuple().
   split_host_port(HostPort, DefaultPort) ->
  -    split_host_port(HostPort, DefaultPort, misc:get_env_default(ns_server, ipv6, false)).
  +    split_host_port(HostPort, DefaultPort, misc:is_ipv6()).
   
   -spec split_host_port(list(), list(), boolean()) -> tuple().
   split_host_port("[" ++ Rest, DefaultPort, true) ->
  
positive.code: 
  -spec get_proto_dist_type() -> string().
  get_proto_dist_type() ->
      case get_env_default(ns_server, ipv6, false) of
          true ->
              "inet6_tcp";
          false ->
  
negative.code: 
  -spec localhost([] | [url]) -> string().
  localhost(Options) ->
      case misc:is_ipv6() of
          true ->
              case Options of
                  [] ->
  