public final class TutorialBlocks {
    [...]
    
    // For versions before 1.21.2
    // public static final DemoBlock DEMO_BLOCK = register("demo_block", new DemoBlock(AbstractBlock.Settings.create()));
    
    // For version 1.21.2 and later
    public static final DemoBlock DEMO_BLOCK = register("demo_block", DemoBlock::new, AbstractBlock.Settings.create());
    
    [...]
}