code: func (w *Watchdog) mapDependencies() {
  	for name := range w.services {
  		svc := w.services[name]
  		for depName := range svc.dependencies {
  			dep, ok := w.services[depName]
  			if !ok {
  				log.Fatalf("Failed to find dependency %q for service %q", depName, name)
  			}
  			svc.dependencies[depName] = dep
  			dep.dependents[svc.name] = svc
  		}
  	}
  }
docs: // mapDependencies maps service dependency names to configured services.