setParent(componentId, parentId) {
    if (!isUndefined(parentId)) {
      this.get(componentId).parentId = parentId;
      this._addChildId(parentId, componentId);
    } else {
      this.rootId = componentId;
    }
  }
Set the parent ID of a component
@param {ComponentId} componentId Id of the component
@param {ComponentId} parentId Id of the parent
@returns {void}