val tags = EmptyTags
    val atomicTags = AtomicReference<Tags>(tags)
    val result =
      atomicTags.computeIfAbsent(String::class) {
        // 'Race' by making another computeIfAbsent call. In practice this would be another thread.
        assertThat(atomicTags.computeIfAbsent(Integer::class) { 5 as Integer }).isEqualTo(5)
        "a"
      }
    assertThat(result).isEqualTo("a")

      Thread.interrupted();
    }
  }

  /**
   * awaitFullGc() is not quite as reliable a way to ensure calling of a specific finalize method as
   * the more direct await* methods, but should be reliable enough in practice to avoid flakiness of
   * this test. (And if it isn't, we'd like to know about it first!)
   */
  public void testAwaitFullGc() {
    CountDownLatch finalizerRan = new CountDownLatch(1);
    WeakReference<Object> ref =

      Thread.interrupted();
    }
  }

  /**
   * awaitFullGc() is not quite as reliable a way to ensure calling of a specific finalize method as
   * the more direct await* methods, but should be reliable enough in practice to avoid flakiness of
   * this test. (And if it isn't, we'd like to know about it first!)
   */
  public void testAwaitFullGc() {
    CountDownLatch finalizerRan = new CountDownLatch(1);
    WeakReference<Object> ref =

If you have many settings that possibly change a lot, maybe in different environments, it might be useful to put them on a file and then read them from it as if they were environment variables.

This practice is common enough that it has a name, these environment variables are commonly placed in a file `.env`, and the file is called a "dotenv".

/// tip

To learn more about <a href="https://docs.pydantic.dev/" class="external-link" target="_blank">Pydantic, check its docs</a>.

///

**FastAPI** is all based on Pydantic.

You will see a lot more of all this in practice in the [Tutorial - User Guide](tutorial/index.md){.internal-link target=_blank}.

/// tip

   * (key) bits 'affects' a strictly smaller set of output bits. Funneling is bad because it can
   * result in more-than-ideal collisions for a non-uniformly distributed key space. In practice,
   * most key spaces are ANYTHING BUT uniformly distributed. A bit(i) in the input is said to
   * 'affect' a bit(j) in the output if two inputs, identical but for bit(i), will differ at output
   * bit(j) about half the time

   * (key) bits 'affects' a strictly smaller set of output bits. Funneling is bad because it can
   * result in more-than-ideal collisions for a non-uniformly distributed key space. In practice,
   * most key spaces are ANYTHING BUT uniformly distributed. A bit(i) in the input is said to
   * 'affect' a bit(j) in the output if two inputs, identical but for bit(i), will differ at output
   * bit(j) about half the time

	// Test that a slice of Association can be used
	associations := []clause.Association{
		{Association: "Orders", Type: clause.OpDelete},
		{Association: "Profiles", Type: clause.OpUpdate},
	}

	// In practice, each Association would be processed individually
	// since []clause.Association doesn't implement AssociationAssigner directly
	for i, assoc := range associations {
		assigns := assoc.AssociationAssignments()

   * worry that we might trigger the fallback to the JDK-backed implementation? (The varargs one
   * _could_, so we could keep it as it is. Or we could convince ourselves that hash flooding is
   * unlikely in practice there, too.)
   */

  /**
   * Returns an immutable set containing the given elements, minus duplicates, in the order each was

   * to the cache because we incorrectly assumed that HttpsURLConnection was always HTTPS and
   * HttpURLConnection was always HTTP; in practice redirects mean that each can do either.
   *
   * https://github.com/square/okhttp/issues/214
   */
  @Test
  fun secureResponseCachingAndProtocolRedirects() {