protected void applyCommand(
@NotNull Command command) {
if (command instanceof Forward) {
activityForward((Forward) command);
} else if (command instanceof Replace) {
activityReplace((Replace) command);
} else if (command instanceof BackTo) {
backTo((BackTo) command);
} else if (command instanceof Back) {
fragmentBack();
}
} вот этот код нарушает LSP ?