constructor() {
      super();
      // maps items to their widths
      this._breadcrumbItemWidths = new WeakMap();
      // the width of the interactive element that opens the overflow
      this._dropdownArrowLinkWidth = 0;
      this._itemNavigation = new _ItemNavigation.default(this, {
        navigationMode: _NavigationMode.default.Horizontal,
        getItemsCallback: () => this._getFocusableItems()
      });
      this._onResizeHandler = this._updateOverflow.bind(this);
      this._labelFocusAdaptor = {
        id: `${this._id}-labelWrapper`,
        getlabelWrapper: this.getCurrentLocationLabelWrapper.bind(this),
        set _tabIndex(value) {
          const wrapper = this.getlabelWrapper();
          wrapper && wrapper.setAttribute("tabindex", value);
        },
        get _tabIndex() {
          const wrapper = this.getlabelWrapper();
          return wrapper?.getAttribute("tabindex") || "";
        }
      };
    }
@class

<h3 class="comment-api-title">Overview</h3>
Enables users to navigate between items by providing a list of links to previous steps in the user's navigation path.
It helps the user to be aware of their location within the application and allows faster navigation.
<br><br>
The last three steps can be accessed as links directly, while the remaining links prior to them are available
in a drop-down menu.
<br><br>
You can choose the type of separator to be used from a number of predefined options.

<h3>Keyboard Handling</h3>
The <code>ui5-breadcrumbs</code> provides advanced keyboard handling.
<br>
<ul>
<li>[F4, ALT+UP, ALT+DOWN, SPACE, ENTER] - If the dropdown arrow is focused - opens/closes the drop-down.</li>
<li>[SPACE, ENTER] - Activates the focused item and triggers the <code>item-click</code> event.</li>
<li>[ESC] - Closes the drop-down.</li>
<li>[LEFT] - If the drop-down is closed - navigates one item to the left.</li>
<li>[RIGHT] - If the drop-down is closed - navigates one item to the right.</li>
<li>[UP] - If the drop-down is open - moves focus to the next item.</li>
<li>[DOWN] - If the drop-down is open - moves focus to the previous item.</li>
<li>[HOME] - Navigates to the first item.</li>
<li>[END] - Navigates to the last item.</li>
</ul>
<br>
@constructor
@author SAP SE
@alias sap.ui.webc.main.Breadcrumbs
@extends sap.ui.webc.base.UI5Element
@tagname ui5-breadcrumbs
@appenddocs sap.ui.webc.main.BreadcrumbsItem
@public
@since 1.0.0-rc.15