public PrimeController(IPrimeSearcher primeSearcher, IHealthCheckCounter healthCheckCounter)
 {
     this.primeSearcher      = primeSearcher ?? throw new ArgumentNullException(nameof(primeSearcher));
     this.healthCheckCounter = healthCheckCounter ?? throw new ArgumentNullException(nameof(healthCheckCounter));
 }
 public CounterHealthCheck(IHealthCheckCounter healthCheckCounter)
 {
     // Use dependency injection (DI) to supply any required services to the
     // health check.
     this.healthCheckCounter = healthCheckCounter;
 }