Updated the custom stone block in demo

src/test/java/demo/Main.java

@@ -1,7 +1,7 @@
 package demo;
 
 import demo.blocks.BurningTorchBlock;
-import demo.blocks.StoneBlock;
+import demo.blocks.CustomBlockSample;
 import demo.blocks.UpdatableBlockDemo;
 import demo.commands.*;
 import net.minestom.server.MinecraftServer;
@@ -23,7 +23,7 @@ public class Main {
         // MinecraftServer.setShouldProcessNettyErrors(true);
 
         BlockManager blockManager = MinecraftServer.getBlockManager();
-        blockManager.registerCustomBlock(new StoneBlock());
+        blockManager.registerCustomBlock(new CustomBlockSample());
         blockManager.registerCustomBlock(new UpdatableBlockDemo());
         blockManager.registerCustomBlock(new BurningTorchBlock());
 

src/test/java/demo/PlayerInit.java

@@ -5,8 +5,6 @@ import demo.generator.NoiseTestGenerator;
 import net.minestom.server.MinecraftServer;
 import net.minestom.server.benchmark.BenchmarkManager;
 import net.minestom.server.chat.ColoredText;
-import net.minestom.server.data.Data;
-import net.minestom.server.data.DataImpl;
 import net.minestom.server.entity.*;
 import net.minestom.server.entity.damage.DamageType;
 import net.minestom.server.entity.type.monster.EntityZombie;
@@ -26,6 +24,7 @@ import net.minestom.server.inventory.InventoryType;
 import net.minestom.server.item.ItemStack;
 import net.minestom.server.item.Material;
 import net.minestom.server.network.ConnectionManager;
+import net.minestom.server.network.packet.server.play.EffectPacket;
 import net.minestom.server.network.packet.server.play.PlayerListHeaderAndFooterPacket;
 import net.minestom.server.ping.ResponseDataConsumer;
 import net.minestom.server.utils.PacketUtils;
@@ -34,6 +33,7 @@ import net.minestom.server.utils.Vector;
 import net.minestom.server.utils.time.TimeUnit;
 import net.minestom.server.world.DimensionType;
 
+import java.util.Collection;
 import java.util.UUID;
 import java.util.concurrent.ThreadLocalRandom;
 
@@ -74,6 +74,12 @@ public class PlayerInit {
         BenchmarkManager benchmarkManager = MinecraftServer.getBenchmarkManager();
 
         MinecraftServer.getSchedulerManager().buildTask(() -> {
+
+            Collection<Player> players = connectionManager.getOnlinePlayers();
+
+            if (players.isEmpty())
+                return;
+
             long ramUsage = benchmarkManager.getUsedMemory();
             ramUsage /= 1e6; // bytes to MB
 
@@ -85,7 +91,7 @@ public class PlayerInit {
                 playerListHeaderAndFooterPacket.header = header;
                 playerListHeaderAndFooterPacket.footer = footer;
 
-                PacketUtils.sendGroupedPacket(connectionManager.getOnlinePlayers(), playerListHeaderAndFooterPacket);
+                PacketUtils.sendGroupedPacket(players, playerListHeaderAndFooterPacket);
             }
 
         }).repeat(10, TimeUnit.TICK).schedule();
@@ -205,10 +211,7 @@ public class PlayerInit {
             final Player player = event.getPlayer();
             player.setGameMode(GameMode.CREATIVE);
 
-            ItemStack itemStack = new ItemStack(Material.BARRIER, (byte) 64);
-            Data data = new DataImpl();
-            data.set("testc", 2);
-            itemStack.setData(data);
+            ItemStack itemStack = new ItemStack(Material.STONE, (byte) 64);
             player.getInventory().addItemStack(itemStack);
 
             //player.getInventory().addItemStack(new ItemStack(Material.STONE, (byte) 32));

src/test/java/demo/blocks/CustomBlockSample.java

@@ -6,13 +6,18 @@ import net.minestom.server.instance.Instance;
 import net.minestom.server.instance.block.Block;
 import net.minestom.server.instance.block.CustomBlock;
 import net.minestom.server.utils.BlockPosition;
+import net.minestom.server.utils.time.TimeUnit;
+import net.minestom.server.utils.time.UpdateOption;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.Set;
 
-public class StoneBlock extends CustomBlock {
+public class CustomBlockSample extends CustomBlock {
 
-    public StoneBlock() {
+    private static final UpdateOption UPDATE_OPTION = new UpdateOption(3, TimeUnit.TICK);
+
+    public CustomBlockSample() {
         super(Block.GOLD_BLOCK, "custom_block");
     }
 
@@ -23,7 +28,7 @@ public class StoneBlock extends CustomBlock {
 
     @Override
     public void onDestroy(@NotNull Instance instance, @NotNull BlockPosition blockPosition, Data data) {
-        BlockPosition above = blockPosition.copy().add(0, 1, 0);
+        BlockPosition above = blockPosition.clone().add(0, 1, 0);
         CustomBlock blockAbove = instance.getCustomBlock(above);
         if (blockAbove == this) {
             instance.setBlock(above, Block.AIR);
@@ -31,6 +36,18 @@ public class StoneBlock extends CustomBlock {
         }
     }
 
+    @Override
+    public void update(@NotNull Instance instance, @NotNull BlockPosition blockPosition, @Nullable Data data) {
+        final short blockId = instance.getBlockStateId(blockPosition);
+        instance.refreshBlockStateId(blockPosition, (short) (blockId+1));
+    }
+
+    @Nullable
+    @Override
+    public UpdateOption getUpdateOption() {
+        return UPDATE_OPTION;
+    }
+
     @Override
     public void updateFromNeighbor(@NotNull Instance instance, @NotNull BlockPosition thisPosition, @NotNull BlockPosition neighborPosition, boolean directNeighbor) {