Es gibt viele Situationen, in denen Sie einem Client, der Ihre API benutzt, einen Fehler zurückgeben müssen.

Dieser Client könnte ein Browser mit einem Frontend, Code von jemand anderem, ein <abbr title="Internet of Things – Internet der Dinge: Geräte, die über das Internet Informationen austauschen">IoT</abbr>-Gerät, usw., sein.

Sie müssten beispielsweise einem Client sagen:

 * the current thread leaves the monitor cleanly:
 *
 * {@snippet :
 * if (monitor.tryEnter()) {
 *   try {
 *     // do things while occupying the monitor
 *   } finally {
 *     monitor.leave();
 *   }
 * } else {
 *   // do other things since the monitor was not available
 * }
 * }
 *
 * <h2>Comparison with {@code synchronized} and {@code ReentrantLock}</h2>
 *

### Summary { #summary }

I used to say I didn't like history that much... and look at me now giving "tech history" lessons. 😅

These custom validators are for things that can be checked with **only** the **same data** provided in the request.

///

### Understand that Code { #understand-that-code }

This idea of **asynchronous** code described above is also sometimes called **"concurrency"**. It is different from **"parallelism"**.

**Concurrency** and **parallelism** both relate to "different things happening more or less at the same time".

But the details between *concurrency* and *parallelism* are quite different.

To see the difference, imagine the following story about burgers:

             * request. However the chances are slim and the
             * retry code should ensure the overall request
             * is serviced. The alternative complicates things
             * more than I think is worth it.
             */

            if (socket != null) {
                socket.close();
                socket = null;
            }
            thread = null;

        .inOrder();
  }

  public void testCopyOf_array_empty() {
    /*
     * We don't guarantee the same-as property, so we aren't obligated to test it. However, it's
     * useful in testing - when two things are the same then one can't have bugs the other doesn't.
     */
    assertThat(ImmutableLongArray.copyOf(new long[0])).isSameInstanceAs(ImmutableLongArray.of());
  }

  public void testCopyOf_array_nonempty() {

///

To **learn the basics of HTTPS**, from a consumer perspective, check <a href="https://howhttps.works/" class="external-link" target="_blank">https://howhttps.works/</a>.

Now, from a **developer's perspective**, here are several things to keep in mind while thinking about HTTPS:

* For HTTPS, **the server** needs to **have "certificates"** generated by a **third party**.
    * Those certificates are actually **acquired** from the third party, not "generated".

`max_sleep` and `max_io` values thereby increasing the healing speed. The delays between each operation of the healer can be adjusted by the `mc admin config set alias/ heal max_sleep=1s` and maximum concurrent requests allowed before we start slowing things down can be configured with `mc admin config set alias/ heal max_io=30` . By default the wait delay is `250ms` beyond 100 concurrent operations. This means the healer will sleep *250 milliseconds* at max for each heal operation if there are more than...

And also that your code will be very compatible with many other Python tools and libraries. 🚀

///

## Type hints in **FastAPI** { #type-hints-in-fastapi }

**FastAPI** takes advantage of these type hints to do several things.

With **FastAPI** you declare parameters with type hints and you get:

* **Editor support**.
* **Type checks**.

...and **FastAPI** uses the same declarations to: