Added DrawingObjectArtillery serialization and deserialization

DrawingObjectArtillery.java

@@ -38,4 +38,16 @@ public class DrawingObjectArtillery implements IDrawingObject {
     public void drawingObject(Graphics2D g) {
         _artillery.drawTransport(g);
     }
+
+    public String getInfo() {
+        if (_artillery == null) {
+            return null;
+        }
+
+        return ArtillerySerde.serialize(_artillery);
+    }
+
+    public static IDrawingObject create(String data) {
+        return new DrawingObjectArtillery(ArtillerySerde.deserialize(data));
+    }
 }

IDrawingObject.java

@@ -6,4 +6,5 @@ public interface IDrawingObject {
     void moveObject(Direction direction);
     void drawingObject(Graphics2D g);
     float[] getCurrentPosition();
+    String getInfo();
 }