Method lock

tests/unit-tests/shell/test_basic_idle_handler.cpp:55–60

{
public:
    void lock() override
    {
        auto config_observer = observer.lock();
        EXPECT_THAT(config_observer, testing::NotNull());
        config_observer->on_lock();
    }
    void unlock() override
    {
        auto config_observer = observer.lock();