Interface AddressResolver

core/src/main/java/io/grpc/internal/DnsNameResolver.java:590–593

AddressResolver resolves a hostname into a list of addresses.

   * AddressResolver resolves a hostname into a list of addresses.
   */
  @VisibleForTesting
  public interface AddressResolver {
    List<InetAddress> resolveAddress(String host) throws Exception;
  }

  private enum JdkAddressResolver implements AddressResolver {
    INSTANCE;