i'm very eepy, but it compiles and works normally if you don't interact with the group system uwu

src/main/java/de/lunarakai/minecleaner/commands/groups/AcceptCommand.java

@@ -0,0 +1,54 @@
+package de.lunarakai.minecleaner.commands.groups;
+
+import de.iani.cubesideutils.bukkit.commands.SubCommand;
+import de.iani.cubesideutils.bukkit.commands.exceptions.*;
+import de.iani.cubesideutils.commands.ArgsParser;
+import de.lunarakai.minecleaner.MinecleanerPlugin;
+import net.kyori.adventure.text.Component;
+import net.kyori.adventure.text.format.NamedTextColor;
+import org.bukkit.Bukkit;
+import org.bukkit.command.Command;
+import org.bukkit.command.CommandSender;
+import org.bukkit.entity.Player;
+
+public class AcceptCommand extends SubCommand {
+    private final MinecleanerPlugin plugin;
+
+    public AcceptCommand(MinecleanerPlugin plugin) {
+        this.plugin = plugin;
+    }
+
+    @Override
+    public String getUsage() {
+        return "";
+    }
+
+    @Override
+    public boolean requiresPlayer() {
+        return true;
+    }
+
+    @Override
+    public String getRequiredPermission() {
+        return MinecleanerPlugin.PERMISSION_PLAY;
+    }
+
+    @Override
+    public boolean onCommand(CommandSender commandSender, Command command, String s, String s1, ArgsParser argsParser) throws DisallowsCommandBlockException, RequiresPlayerException, NoPermissionException, IllegalSyntaxException, InternalCommandException {
+        Player player = (Player) commandSender;
+
+        if(plugin.getGroupManager().getInvitedGroup(player) != null && plugin.getGroupManager().getGroup(player) == null) {
+            Player groupOwner = Bukkit.getPlayer(plugin.getGroupManager().getInvitedGroup(player).getOwner());
+            plugin.getGroupManager().getInvitedGroup(player).addPlayerToGroup(player);
+
+            assert groupOwner != null;
+            groupOwner.sendMessage(Component.text(player.getName() + " hat deine Einladung angenommen.", NamedTextColor.GREEN));
+            player.sendMessage(Component.text("Du hast die Einladung angenommen", NamedTextColor.GREEN));
+
+            return true;
+        } else {
+            player.sendMessage(Component.text("Du wurdest in keine Gruppe eingeladen.", NamedTextColor.YELLOW));
+        }
+        return true;
+    }
+}