如何在网格标题中隐藏排序号

我正在使用angularjs ui网格。我对4列进行了排序,但在我的网格中,我可以看到我想要隐藏这些排序号的排序号。我没有找到任何api配置或解决方案。谢谢

columnDefs: [
                {
                    name: 'name',
                    displayName: "",
                    width: '48%',
                    grouping: {groupPriority: 0},
                    sort: {priority: 0, direction: 'asc'}
                },
                {
                    name: 'id',
                    displayName: "",
                    sort: {priority: 2, direction: 'asc'}
                },
                {
                    name: 'bar',
                    displayName: "",
                    sort: {priority: 3, direction: 'asc'}
                },
                {
                    name: 'foo',
                    displayName: "",
                    sort: {priority: 1, direction: 'asc'}
                }
            ],