I have to import @NonNull but can not find out using Alt Enter in Windows, what steps have to do to import @NonNull class in java.

private Toaster(@NonNull Context context) {
    weakReference = new WeakReference<>(context);
}

public static Toaster getInstance(@NonNull Context context) {
    if (toaster == null) {
        toaster = new Toaster(context.getApplicationContext());
    }
    return toaster;
}