code: public ApnsClientBuilder setApnsServer(final String hostname, final int port) {
          this.apnsServerAddress = InetSocketAddress.createUnresolved(hostname, port);
          return this;
      }
docs: Sets the hostname and port of the server to which the client under construction will connect. Apple provides a
  production and development environment, both of which listen for traffic on the default HTTPS port
  ({@value DEFAULT_APNS_PORT}) and an alternate port ({@value ALTERNATE_APNS_PORT}), which callers may use to work
  around firewall or proxy restrictions.
  
  @param hostname the hostname of the server to which the client under construction should connect
  @param port the port to which the client under contruction should connect
  
  @return a reference to this builder
  
  @see ApnsClientBuilder#DEVELOPMENT_APNS_HOST
  @see ApnsClientBuilder#PRODUCTION_APNS_HOST
  @see ApnsClientBuilder#DEFAULT_APNS_PORT
  @see ApnsClientBuilder#ALTERNATE_APNS_PORT
  
  @see <a href="https://developer.apple.com/documentation/usernotifications/setting_up_a_remote_notification_server/sending_notification_requests_to_apns">Sending Notification Requests to APNs</a>
  
  @since 0.11