@SuppressWarnings("ThreadPriorityCheck") // doing our best to test for races
              public void realRun() {
                while (!a.compareAndSet(0, 2.0, 3.0)) {
                  Thread.yield();
                }
              }
            });

    assertTrue(a.compareAndSet(0, 1.0, 2.0));
    awaitTermination(t);
    assertBitEquals(3.0, a.get(0));
  }

  void awaitTimedWaiting(Thread thread) {
    while (true) {
      switch (thread.getState()) {
        case BLOCKED:
        case NEW:
        case RUNNABLE:
        case WAITING:
          Thread.yield();
          break;
        case TIMED_WAITING:
          return;
        case TERMINATED:
          throw new AssertionError();
      }
    }
  }

Uma **`Session`** é o que armazena os **objetos na memória** e acompanha as alterações necessárias nos dados, para então **usar o `engine`** para se comunicar com o banco de dados.

Vamos criar uma **dependência** do FastAPI com `yield` que fornecerá uma nova `Session` para cada requisição. Isso é o que garante que usamos uma única sessão por requisição. 🤓

   * Returns a big-endian representation of {@code value} in an 8-element byte array; equivalent to
   * {@code ByteBuffer.allocate(8).putLong(value).array()}. For example, the input value {@code
   * 0x1213141516171819L} would yield the byte array {@code {0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
   * 0x18, 0x19}}.
   *
   * <p>If you need to convert and concatenate several values (possibly even of different types),

   * ```
   *   pinnedRoot (trusted by CertificatePinner)
   *     -> pinnedIntermediate (trusted by CertificatePinner)
   *         -> attackerSwitch
   * ```
   *
   * The attacker serves a set of certificates that yields a too-long chain in our certificate
   * pinner. The served certificates (incorrectly) formed a single chain to the pinner:
   *
   * ```
   *   attackerCa
   *     -> attackerIntermediate

        throw new IllegalArgumentException("Trailing high surrogate at end of input");
      }
      // It is possible for this to return null because nextEscapeIndex() may
      // (for performance reasons) yield some false positives but it must never
      // give false negatives.
      char[] escaped = escape(cp);
      int nextIndex = index + (Character.isSupplementaryCodePoint(cp) ? 2 : 1);
      if (escaped != null) {

        throw new IllegalArgumentException("Trailing high surrogate at end of input");
      }
      // It is possible for this to return null because nextEscapeIndex() may
      // (for performance reasons) yield some false positives but it must never
      // give false negatives.
      char[] escaped = escape(cp);
      int nextIndex = index + (Character.isSupplementaryCodePoint(cp) ? 2 : 1);
      if (escaped != null) {

A **`Session`** is what stores the **objects in memory** and keeps track of any changes needed in the data, then it **uses the `engine`** to communicate with the database.

We will create a FastAPI **dependency** with `yield` that will provide a new `Session` for each request. This is what ensures that we use a single session per request. 🤓

Then we create an `Annotated` dependency `SessionDep` to simplify the rest of the code that will use this dependency.

    void awaitWaiting() {
      while (!isBlocked()) {
        if (getState() == State.TERMINATED) {
          throw new RuntimeException("Thread exited");
        }
        Thread.yield();
      }
    }

    private boolean isBlocked() {
      return getState() == Thread.State.WAITING && LockSupport.getBlocker(this) == future;
    }
  }

  /**
   * Divides an iterable into unmodifiable sublists of the given size (the final iterable may be
   * smaller). For example, partitioning an iterable containing {@code [a, b, c, d, e]} with a
   * partition size of 3 yields {@code [[a, b, c], [d, e]]} -- an outer iterable containing two
   * inner lists of three and two elements, all in the original order.
   *