code: function open(bool) {
      // Open
      if (bool || typeof bool === 'undefined') {
        // If present closes an opened instance of the plugin
        // Only one at time can be open
        const openedCustomSelect =
          document.querySelector(`.${containerClass}.${builderParams.isOpenClass}`);
        if (openedCustomSelect) {
          openedCustomSelect.customSelect.open = false;
        }
  
        // Opens only the clicked one
        container.classList.add(builderParams.isOpenClass);
  
        // aria-expanded update
        container.classList.add(builderParams.isOpenClass);
        opener.setAttribute('aria-expanded', 'true');
  
        // Updates the scrollTop position of the panel in relation with the focused option
        if (selectedElement) {
          panel.scrollTop = selectedElement.offsetTop;
        }
  
        // Dispatches the custom event open
        container.dispatchEvent(new CustomEvent('custom-select:open'));
  
        // Sets the global state
        isOpen = true;
  
      // Close
      } else {
        // Removes the css classes
        container.classList.remove(builderParams.isOpenClass);
  
        // aria-expanded update
        opener.setAttribute('aria-expanded', 'false');
  
        // Sets the global state
        isOpen = false;
  
        // When closing the panel the focused custom option must be the selected one
        setFocusedElement(selectedElement);
  
        // Dispatches the custom event close
        container.dispatchEvent(new CustomEvent('custom-select:close'));
      }
      return isOpen;
    }
docs: Open/Close function (toggle)