anchor.diff:      {{ok, [occi_extension:t()]} | {error, erocci_backend:error()}, NewState :: term()}.
   models(#state{ proxy=Backend }=S) ->
       ?info("[~s] models()", [?MODULE]),
  -    case dbus_proxy:call(Backend, ?IFACE_BACKEND, <<"Models">>) of
  +    case dbus_proxy:call(Backend, ?IFACE_BACKEND, <<"Models">>, []) of
   	{ok, Schemas} ->
   	    parse_models(Schemas, [], S);
   	{error, _}=Err ->
  
positive.code: 				 [ << MixinScheme/binary, MixinTerm/binary >> | Acc ]
  			 end, [], occi_entity:mixins(Entity)),
  	     occi_entity:raw_attributes(Entity),
  	     Owner,
  	     Group
  	   ],
      case dbus_proxy:call(Backend, ?IFACE_BACKEND, <<"Create2">>, Args) of
  	{ok, [Location, KindId, MixinIds, Attributes, Serial]} ->
  	    Entity2 = unmarshal_entity(KindId, MixinIds, Attributes),
  	    {{ok, occi_entity:location(Location, Entity2), unmarshal_serial(Serial)}, S};
  	{error, _}=Err ->
  	    {Err, S}
      end.
  
  
  
negative.code: 		    {ok | {error, erocci_backend:error()}, NewState :: term()}.
  delete(Location, #state{ proxy=Backend }=S) ->
      ?info("[~p] delete(~s)", [?MODULE, Location]),
      case dbus_proxy:call(Backend, ?IFACE_BACKEND, [Location]) of
  	ok ->
  	    {ok, S};
  	{error, Err} ->
  	    dbus_errors(Err, S)
      end.
  
  
  -spec mixin(Location :: occi_uri:url(), MixinId :: occi_mixin:t(), Attributes :: maps:map(), State :: term()) ->
  