dogstatsd

Measures the in-process DogStatsD egress formatting that every runtime and custom metric runs through: DogStatsDClient._add builds the stat:value|type line, splices global and per-metric tags, and appends to the 1KB datagram buffer. The aggregated variant drives the MetricsAggregationClient tag tree that runtime metrics accumulate before flushing. The UDP socket is stubbed; nothing leaves the process.