public XnaObject(GraphicsManager graphicsManager, string fileName = null)
 {
     _fileName = fileName;
     GraphicsManager = graphicsManager;
     _position = Vector2.Zero;
     _color = Color.White;
     _rotation = 0f;
     _scale = 1f;
     _origin = Vector2.Zero;
 }
 public Molecula(GraphicsManager graphicsManager, string fileName = null)
     : base(graphicsManager, fileName)
 {
     Massa = 10;
 }