code: func (api *Api) Stat(send helper.StatCallback) {
  	helper.SendAndSubstractUint32("cacheRequests", &api.stat.cacheRequests, send)
  	helper.SendAndSubstractUint32("cacheRequestMetrics", &api.stat.cacheRequestMetrics, send)
  	helper.SendAndSubstractUint32("cacheResponseMetrics", &api.stat.cacheResponseMetrics, send)
  	helper.SendAndSubstractUint32("cacheResponsePoints", &api.stat.cacheResponsePoints, send)
  }
docs: // Collect cache metrics