fixed a few little things

include/ConstructionWrapper.hh

@@ -43,6 +43,11 @@ public:
     void setIsActive(bool isActive);
     void assignPhysicalVolume(G4VPhysicalVolume* physicalVolume);
 
+    void unAssign(){
+        physicalVolume = nullptr;
+        sensors.clear();
+    }
+
     double thickness;
     double sens_xwidth;
     double sens_ywidth;
@@ -99,6 +104,12 @@ public:
         }
     }
 
+    void unAssign(){
+        for(auto& layer: layers){
+            layer.unAssign();
+        }
+    }
+
 
 private:
     double xywidth;