code: function removeChildrenL2(data = []) {
    const ds = cloneDeep(data);
    ds.forEach((item) => {
      if (item.children) {
        item.children.forEach((subItem) => {
          if (subItem.children) {
            delete subItem.children;
          }
        });
      }
    });
    return ds;
  }
docs: 删除市节点下所有的子节点
  
  @param {any} [data=[]]
  @returns