/**
     * Attach event listeners.
     * @param {HTMLMenuElement} html  The root menu element.
     */
    activateListeners(html) {
      if ( !this.#onAction ) return;
      html.querySelectorAll(`.pm-dropdown.${this.#cssClass} li`).forEach(item => {
        item.addEventListener("click", event => {
          this.#onAction(event);
        });
      });
    }

    /**
     * Attach event listeners.
     * @param {HTMLMenuElement} html  The root menu element.
     */
    activateListeners(html) {
      if ( !this.#onAction ) return;
      html.querySelectorAll(`.pm-dropdown.${this.#cssClass} li`).forEach(item => {
        item.addEventListener("click", event => {
          this.#onAction(event);
        });
      });
    }

   async sortRelative({updateData={}, ...sortOptions}={}) {
      const sorting = SortingHelpers.performIntegerSort(this, sortOptions);
      const updates = [];
      for ( let s of sorting ) {
        const doc = s.target;
        const update = foundry.utils.mergeObject(updateData, s.update, {inplace: false});
        update._id = doc._id;
        if ( doc.sheet && doc.sheet.rendered ) await doc.sheet.submit({updateData: update}); // <------------- HERE!
        else updates.push(update);
      }
      if ( updates.length ) await this.constructor.updateDocuments(updates, {parent: this.parent, pack: this.pack});
      return this;
    }

   async sortRelative({updateData={}, ...sortOptions}={}) {
      const sorting = SortingHelpers.performIntegerSort(this, sortOptions);
      const updates = [];
      for ( let s of sorting ) {
        const doc = s.target;
        const update = foundry.utils.mergeObject(updateData, s.update, {inplace: false});
        update._id = doc._id;
        if ( doc.sheet && doc.sheet.rendered ) await doc.sheet.submit({updateData: update}); // <------------- HERE!
        else updates.push(update);
      }
      if ( updates.length ) await this.constructor.updateDocuments(updates, {parent: this.parent, pack: this.pack});
      return this;
    }