expandAll() {
    this.#nodes.filter((n) => n.elem.isGroup).forEach((n) => {
      n.elem.expanded = true;
    });
  }
/**
   * Expand all attached nodes to the tree
   * @returns {void}
   */
Expand all attached nodes to the tree
@returns {void}
Expand all attached nodes to the tree @returns { void }
expandAll() {
    this.#nodes.filter((n) => n.elem.isGroup).forEach((n) => {
      n.elem.expanded = true;
    });
  }
expandAll ( ) { this . #nodes . filter ( ( n ) => n . elem . isGroup ) . forEach ( ( n ) => { n . elem . expanded = true ; } ) ; }
Expand all attached nodes to the tree
 @returns {void}
Expand all attached nodes to the tree @returns { void }