anchor.diff:          <p>Add <strong>SVG shapes</strong> to canvas:</p>
   
           <ul class="svg-shapes">
  +          <li>
  +            <button class="fix-width-btn" onclick="addWall()">
  +              <img src="https://upload.wikimedia.org/wikipedia/commons/thumb/d/d1/Brick_wall_close-up_view.jpg/640px-Brick_wall_close-up_view.jpg" width="150px" height="150px"> <br>
  +
  +            </button>
  +            <div class="container-fluid description">
  +              <strong>Wall</strong>
  +            </div>
  +          </li>
             <% ElementType.all.each do |type| %>
  +              <% if type.id < 39 %>
                 <li>
                   <button class="fix-width-btn" id="<%= type.id %>" onclick="addShape(<%= type.id %>, '<%= asset_path(type.svg_path + ".svg") %>')">
                     <img src="<%= asset_path(type.svg_path + ".svg") %>" width="150px" height="150px"> <br> 
  
positive.code:       data : { svg_data: data }
      });
  
      canvas.width = w;
      canvas.height = h;
      canvas.add(grid);
  
negative.code:                     <strong><%= type.name %></strong>
                    </div>
                </li>
                    <% end %>
            <% end %>
          </ul>
        </div>
  