anchor.diff:        data : { svg_data: data }
       });
   
  +    restoreWallCircles();
       canvas.width = w;
       canvas.height = h;
       canvas.add(grid);
  
positive.code:                     <strong><%= type.name %></strong>
                    </div>
                </li>
            <% end %>
          </ul>
        </div>
  
negative.code:     canvas.width = 6003;
      canvas.height = 4003;
      canvas.remove(grid);
      removeWallCircles();
  
      var data = canvas.toSVG()
      $.ajax({
  