long callId = nextCallId.getAndIncrement();
      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;
  }

document's age at the time it was served based on "Last-Modified". Default expiration dates aren't used for URIs
containing a query.

 - CallStart
 - **CacheHit**
 - CallEnd

### Cache Miss

Under a cache miss the normal request events are seen but an additional event shows the presence of the cache.

          call: Call,
          byteCount: Long,
        ) = TODO()

        override fun responseFailed(
          call: Call,
          ioe: IOException,
        ) = TODO()

        override fun callEnd(call: Call) = TODO()

        override fun callFailed(
          call: Call,
          ioe: IOException,
        ) = TODO()

        override fun canceled(call: Call) = TODO()
      }

  }

  @Test
  fun postWithFileNotFound() {
    val called = AtomicInteger(0)
    val body: RequestBody =
      object : RequestBody() {
        override fun contentType(): MediaType = "application/octet-stream".toMediaType()

        override fun writeTo(sink: BufferedSink) {
          called.incrementAndGet()
          throw FileNotFoundException()
        }
      }

	public fun <init> ()V
	public fun cacheConditionalHit (Lokhttp3/Call;Lokhttp3/Response;)V
	public fun cacheHit (Lokhttp3/Call;Lokhttp3/Response;)V
	public fun cacheMiss (Lokhttp3/Call;)V
	public fun callEnd (Lokhttp3/Call;)V
	public fun callFailed (Lokhttp3/Call;Ljava/io/IOException;)V
	public fun callStart (Lokhttp3/Call;)V
	public fun canceled (Lokhttp3/Call;)V

	public fun <init> ()V
	public fun cacheConditionalHit (Lokhttp3/Call;Lokhttp3/Response;)V
	public fun cacheHit (Lokhttp3/Call;Lokhttp3/Response;)V
	public fun cacheMiss (Lokhttp3/Call;)V
	public fun callEnd (Lokhttp3/Call;)V
	public fun callFailed (Lokhttp3/Call;Ljava/io/IOException;)V
	public fun callStart (Lokhttp3/Call;)V
	public fun canceled (Lokhttp3/Call;)V

    FinalizableReference.register(this);
  }

  /**
   * Returns a future that finishes when this step does. Calling {@code get()} on the returned
   * future returns {@code null} if the step is successful or throws the same exception that would
   * be thrown by calling {@code finishToFuture().get()} if this were the last step. Calling {@code
   * cancel()} on the returned future has no effect on the {@code ClosingFuture} pipeline.
   *

Actually, all (or most) of the web frameworks work in this same way.

You never call those functions directly. They are called by your framework (in this case, **FastAPI**).

   * note that the execution order of all listeners is ultimately chosen by the implementations of
   * the supplied executors.
   *
   * <p>This method is idempotent. Calling it several times in parallel is semantically equivalent
   * to calling it exactly once.
   *
   * @since 10.0 (present in 1.0 as {@code run})
   */
  public void execute() {

In an advanced scenario where you know you need the dependency to be called at every step (possibly multiple times) in the same request instead of using the "cached" value, you can set the parameter `use_cache=False` when using `Depends`: