() { reactions.push("disconnected"); }
            });
        const element = document.createElement(element_name);
        t.add_cleanup(() => element.remove());
        document.body.append(element);
        await Promise.resolve();
        reactions = [];
        document.getElementById("section").moveBefore(element, null);
        await Promise.resolve();
        assert_array_equals(reactions, ["connectedMove"]);
    }, "When connectedMoveCallback is defined, it is called instead of disconnectedCallbac