Add a counter beside menu item label

I’m using the following code to add a panel to the admin menu screen, so the users are able to add a Cart link to their menus:

function my_add_meta_box() {     add_meta_box( 'custom-meta-box', __( 'Cart' ), 'my_nav_menu_item_link_meta_box', 'nav-menus', 'side', 'default' ); } add_action( 'admin_init', 'my_add_meta_box' );  function my_nav_menu_item_link_meta_box() {     global $  _nav_menu_placeholder, $  nav_menu_selected_id;     $  _nav_menu_placeholder = 0 > $  _nav_menu_placeholder ? $  _nav_menu_placeholder - 1 : -1;     ?>     <div id="posttype-cart" class="posttypediv">         <div id="tabs-panel-cart" class="tabs-panel tabs-panel-active">             <ul id="cart-checklist" class="categorychecklist form-no-clear">                 <li>                     <label class="menu-item-title">                         <input type="checkbox" class="menu-item-checkbox" name="menu-item[<?php echo (int) $  _nav_menu_placeholder; ?>][menu-item-object-id]" value="-1"> <?php esc_html_e( 'Cart' ); ?>                     </label>                     <input type="hidden" class="menu-item-type" name="menu-item[<?php echo (int) $  _nav_menu_placeholder; ?>][menu-item-type]" value="post_type">                     <input type="hidden" class="menu-item-object" name="menu-item[<?php echo (int) $  _nav_menu_placeholder; ?>][menu-item-object]" value="page">                     <input type="hidden" class="menu-item-object-id" name="menu-item[<?php echo (int) $  _nav_menu_placeholder; ?>][menu-item-object-id]" value="<?php echo get_option( 'cart_page_id' ); ?>">                     <input type="hidden" class="menu-item-title" name="menu-item[<?php echo (int) $  _nav_menu_placeholder; ?>][menu-item-title]" value="<?php esc_html_e( 'Cart' ); ?>">                 </li>             </ul>         </div>         <p class="button-controls">             <span class="add-to-menu">                 <input type="submit" <?php disabled( $  nav_menu_selected_id, 0 ); ?> class="button-secondary submit-add-to-menu right" value="<?php esc_attr_e( 'Add to Menu' ); ?>" name="add-post-type-menu-item" id="submit-posttype-cart">                 <span class="spinner"></span>             </span>         </p>     </div>     <?php } 

My question is, is it possible to dynamically add a counter that shows the number of items in cart beside the Cart menu item label in the frontend? If so, how? I think that the wp_get_nav_menu_items filter might be useful for this, but how can I identify the Cart menu item in there to be able to modify its label in the frontend on the fly?

function my_get_nav_menu_items( $  items ) {     foreach ( $  items as $  item ) {         if ( is_cart_menu_item( $  item ) ) {             // add a counter beside the Cart menu item label             }     }     return items; } add_filter( 'wp_get_nav_menu_items', 'my_get_nav_menu_items', 20 );