code: func Report(c context.Context) {
  	registry.m.RLock()
  	defer registry.m.RUnlock()
  	for component := range registry.r {
  		versionMetric.Set(c, registry.r[component], component)
  	}
  }
docs: // Report populates 'luci/components/version' metric with versions of all
  // registered components.