code: func (pmc *proxyMetricsCollector) ManifestPull(bytesPulled uint64) {
  	atomic.AddUint64(&pmc.manifestMetrics.Misses, 1)
  	atomic.AddUint64(&pmc.manifestMetrics.BytesPulled, bytesPulled)
  }
docs: // ManifestPull tracks metrics related to Manifests pulled into the cache