System.out.printf("%04d %s%n", callId, call.request().url());
      return new PrintingEventListener(callId, System.nanoTime());
    }
  };

  final long callId;
  final long callStartNanos;

  public PrintingEventListener(long callId, long callStartNanos) {
    this.callId = callId;
    this.callStartNanos = callStartNanos;
  }

  private void printEvent(String name) {

        System.out.printf("%04d %s%n", callId, call.request().url());
        return new PrintingEventListener(callId, System.nanoTime());
      }
    };

    final long callId;
    final long callStartNanos;

    PrintingEventListener(long callId, long callStartNanos) {
      this.callId = callId;
      this.callStartNanos = callStartNanos;
    }

    private void printEvent(String name) {

 * because we don't know what callStartNanos refers to.
 */
public final class PrintEventsNonConcurrent {
  private final OkHttpClient client = new OkHttpClient.Builder()
      .eventListener(new PrintingEventListener())
      .build();

  public void run() throws Exception {
    Request request = new Request.Builder()
        .url("https://publicobject.com/helloworld.txt")
        .build();