Window 支持MultiDimension

多维度window支持吗？要如何使用？类似如下场景：

bvar::MultiDimension> mbvar(
"test_count",
{"xx1", "xx2"});
bvar::Window>> counter_1min(&mbvar, 60)

网上搜的方法，貌似不行
auto label = {"v1", "v2"};
counter_1min << std::make_pair(label, 1);

Start at bvar::MultiDimension and bvar::Window, using the issue's example insertion expression as the reproduction case. Determine whether multidimensional window support exists and how it is intended to be used; if not, define the required change and a reproducible test.

Written by the indexing model from the issue text.