How to use the opcua.ua.ObjectIds function in opcua

def check_custom_type(test, type, base_type, node_class=None):
    base = opcua.Node(test.opc.iserver.isession, ua.NodeId(base_type))
    test.assertTrue(type in base.get_children())
    nodes = type.get_referenced_nodes(refs=ua.ObjectIds.HasSubtype, direction=ua.BrowseDirection.Inverse, includesubtypes=True)
    test.assertEqual(base, nodes[0])
    properties = type.get_properties()

    if node_class:
        test.assertEqual(node_class, type.get_node_class())

    test.assertIsNot(properties, None)
    test.assertEqual(len(properties), 2)
    test.assertTrue(type.get_child("2:PropertyNum") in properties)
    test.assertEqual(type.get_child("2:PropertyNum").get_data_value().Value.VariantType, ua.VariantType.Int32)
    test.assertTrue(type.get_child("2:PropertyString") in properties)
    test.assertEqual(type.get_child("2:PropertyString").get_data_value().Value.VariantType, ua.VariantType.String)

def test_data_type_to_variant_type(self):
        test_data = {
            ua.ObjectIds.Boolean: ua.VariantType.Boolean,
            ua.ObjectIds.Byte: ua.VariantType.Byte,
            ua.ObjectIds.String: ua.VariantType.String,
            ua.ObjectIds.Int32: ua.VariantType.Int32,
            ua.ObjectIds.UInt32: ua.VariantType.UInt32,
            ua.ObjectIds.NodeId: ua.VariantType.NodeId,
            ua.ObjectIds.LocalizedText: ua.VariantType.LocalizedText,
            ua.ObjectIds.Structure: ua.VariantType.ExtensionObject,
            ua.ObjectIds.EnumValueType: ua.VariantType.ExtensionObject,
            ua.ObjectIds.Enumeration: ua.VariantType.Int32,  # enumeration
            ua.ObjectIds.AttributeWriteMask: ua.VariantType.UInt32,
            ua.ObjectIds.AxisScaleEnumeration: ua.VariantType.Int32  # enumeration
            }
        for dt, vdt in test_data.items():
            self.assertEqual(ua_utils.data_type_to_variant_type(self.opc.get_node(ua.NodeId(dt))), vdt)

def runTest(self):
        return # FIXME broken
        tmpfile = NamedTemporaryFile()
        path = tmpfile.name
        tmpfile.close()

        # create cache file
        server = Server(shelffile=path)

        # modify cache content
        id = ua.NodeId(ua.ObjectIds.Server_ServerStatus_SecondsTillShutdown)
        s = shelve.open(path, "w", writeback=True)
        s[id.to_string()].attributes[ua.AttributeIds.Value].value = ua.DataValue(123)
        s.close()

        # ensure that we are actually loading from the cache
        server = Server(shelffile=path)
        self.assertEqual(server.get_node(id).get_value(), 123)

        os.remove(path)

def test_eventgenerator_double_customEvent(self):
        event1 = self.opc.create_custom_event_type(3, 'MyEvent1', ua.ObjectIds.BaseEventType, [('PropertyNum', ua.VariantType.Int32), ('PropertyString', ua.VariantType.String)])

        event2 = self.opc.create_custom_event_type(4, 'MyEvent2', event1, [('PropertyBool', ua.VariantType.Boolean), ('PropertyInt', ua.VariantType.Int32)])

        evgen = self.opc.get_event_generator(event2, ua.ObjectIds.Server)
        check_eventgenerator_CustomEvent(self, evgen, event2)
        check_eventgenerator_SourceServer(self, evgen)

        # Properties from MyEvent1
        self.assertEqual(evgen.event.PropertyNum, 0)
        self.assertEqual(evgen.event.PropertyString, None)

         # Properties from MyEvent2
        self.assertEqual(evgen.event.PropertyBool, False)
        self.assertEqual(evgen.event.PropertyInt, 0)

def run(self):
        self.logger.debug("starting keepalive thread with period of %s milliseconds", self.timeout)
        server_state = self.client.get_node(ua.FourByteNodeId(ua.ObjectIds.Server_ServerStatus_State))
        while not self._do_stop:
            with self._cond:
                self._cond.wait(self.timeout / 1000)
            if self._do_stop:
                break
            self.logger.debug("renewing channel")
            self.client.open_secure_channel(renew=True)
            val = server_state.get_value()
            self.logger.debug("server state is: %s ", val)
        self.logger.debug("keepalive thread has stopped")

ref.ReferenceTypeId = ua.NodeId.from_string("i=46")
    ref.SourceNodeId = ua.NodeId.from_string("i=12169")
    ref.TargetNodeClass = ua.NodeClass.DataType
    ref.TargetNodeId = ua.NodeId.from_string("i=120")
    refs.append(ref)
    server.add_references(refs)
   
    node = ua.AddNodesItem()
    node.RequestedNewNodeId = ua.NodeId.from_string("i=3068")
    node.BrowseName = ua.QualifiedName.from_string("NodeVersion")
    node.NodeClass = ua.NodeClass.Variable
    node.TypeDefinition = ua.NodeId.from_string("i=68")
    attrs = ua.VariableAttributes()
    attrs.Description = ua.LocalizedText("The version number of the node (used to indicate changes to references of the owning node).")
    attrs.DisplayName = ua.LocalizedText("NodeVersion")
    attrs.DataType = ua.NodeId(ua.ObjectIds.String)
    attrs.ValueRank = -2
    node.NodeAttributes = attrs
    server.add_nodes([node])
    refs = []
    ref = ua.AddReferencesItem()
    ref.IsForward = True
    ref.ReferenceTypeId = ua.NodeId.from_string("i=40")
    ref.SourceNodeId = ua.NodeId.from_string("i=3068")
    ref.TargetNodeClass = ua.NodeClass.DataType
    ref.TargetNodeId = ua.NodeId.from_string("i=68")
    refs.append(ref)
    server.add_references(refs)
   
    node = ua.AddNodesItem()
    node.RequestedNewNodeId = ua.NodeId.from_string("i=12170")
    node.BrowseName = ua.QualifiedName.from_string("ViewVersion")

if isinstance(val, (list, tuple)):
            if dtype.NamespaceIndex == 0 and dtype.Identifier <= 21:
                elname = "uax:ListOf" + type_name
            else:  # this is an extentionObject:
                elname = "uax:ListOfExtensionObject"

            list_el = Et.SubElement(el, elname)
            for nval in val:
                self._value_to_etree(list_el, type_name, dtype, nval)
        else:
            dtype_base = get_base_data_type(self.server.get_node(dtype))
            dtype_base = dtype_base.nodeid

            if dtype_base == ua.NodeId(ua.ObjectIds.Enumeration):
                dtype_base = ua.NodeId(ua.ObjectIds.Int32)
                type_name = ua.ObjectIdNames[dtype_base.Identifier]

            if dtype_base.NamespaceIndex == 0 and dtype_base.Identifier <= 21:
                type_name = ua.ObjectIdNames[dtype_base.Identifier]
                val_el = Et.SubElement(el, "uax:" + type_name)
                self._val_to_etree(val_el, dtype_base, val)
            else:
                self._extobj_to_etree(el, type_name, dtype, val)

def _get_datatype_from_string(self, idx, name):
        #FIXME: this is very heavy and missing recusion, what is the correct way to do that?
        for node in self.server_mgr.get_node(ua.ObjectIds.BaseDataType).get_children():
            try:
                dtype = node.get_child(f'{idx}:{name}')
            except ua.UaError:
                continue
            return dtype
        return None

def _rdesc_from_node(parent, node):
    results = node.get_attributes([ua.AttributeIds.NodeClass, ua.AttributeIds.BrowseName, ua.AttributeIds.DisplayName])
    nclass, qname, dname = [res.Value.Value for res in results]

    rdesc = ua.ReferenceDescription()
    rdesc.NodeId = node.nodeid
    rdesc.BrowseName = qname
    rdesc.DisplayName = dname
    rdesc.NodeClass = nclass
    if parent.get_type_definition() == ua.NodeId(ua.ObjectIds.FolderType):
        rdesc.ReferenceTypeId = ua.NodeId(ua.ObjectIds.Organizes)
    else:
        rdesc.ReferenceTypeId = ua.NodeId(ua.ObjectIds.HasComponent)
    typedef = node.get_type_definition()
    if typedef:
        rdesc.TypeDefinition = typedef
    return rdesc

def get_node_subtypes(node, nodes=None):
    if nodes is None:
        nodes = [node]
    for child in node.get_children(refs=ua.ObjectIds.HasSubtype):
        nodes.append(child)
        get_node_subtypes(child, nodes)
    return nodes