Add rmoval of empty group

BauSystem_Main/src/de/steamwar/bausystem/features/simulator2/gui/SimulatorGui.java

@@ -31,6 +31,7 @@ import org.bukkit.Material;
 import org.bukkit.entity.Player;
 
 import java.util.ArrayList;
+import java.util.Iterator;
 import java.util.List;
 
 public class SimulatorGui extends SimulatorPageGui<SimulatorGroup> {
@@ -46,7 +47,12 @@ public class SimulatorGui extends SimulatorPageGui<SimulatorGroup> {
 
     @Override
     public void headerAndFooter() {
-        // TODO: Remove empty Groups
+        for(Iterator<SimulatorGroup> i = simulator.getElements().iterator(); i.hasNext();){
+            if(i.next().getElements().isEmpty()){
+                i.remove();
+            }
+        }
+
         inventory.setItem(4, new SWItem(simulator.getMaterial(), "§e" + simulator.getName(), clickType -> {
             new SimulatorMaterialGui(player, simulator, simulator::getMaterial, simulator::setMaterial, this).open();
         }));