* Breaking AtomicReferenceFieldUpdater not only forces AggregateFutureState to fall back to
         * another implementation but also forces AbstractFutureState to be able to do the
         * same—hence the try-catch here.
         *
         * (Really, we're fortunate that breaking AtomicReferenceFieldUpdater doesn't break _even
         * more_ things.)
         */
        helper = new SynchronizedHelper();

do FastAPI.

/// tip | Dica

Para perguntas, pergunte nas <a href="https://github.com/fastapi/fastapi/issues/new/choose" class="external-link" target="_blank">questões do GitHub</a>, lá tem um chance maior de você ser ajudado sobre o FastAPI [FastAPI Experts](fastapi-people.md#especialistas){.internal-link target=_blank}.

Use o chat apenas para outro tipo de assunto.

///

### Não faça perguntas no chat

        entry != null;
        entry = entry.getNextInKeyBucket()) {
      Object candidateKey = entry.getKey();

      /*
       * Assume that equals uses the == optimization when appropriate, and that
       * it would check hash codes as an optimization when appropriate. If we
       * did these things, it would just make things worse for the most
       * performance-conscious users.
       */
      if (key.equals(candidateKey)) {

Then you declare your data model as a class that inherits from `BaseModel`.

Use standard Python types for all the attributes:

{* ../../docs_src/body/tutorial001_py310.py hl[5:9] *}


The same as when declaring query parameters, when a model attribute has a default value, it is not required. Otherwise, it is required. Use `None` to make it just optional.

For example, this model above declares a JSON "`object`" (or Python `dict`) like:

```JSON

```Python
q: str | None = Query(default=None, max_length=50)
```

This will validate the data, show a clear error when the data is not valid, and document the parameter in the OpenAPI schema *path operation*.

### `Query` as the default value or in `Annotated` { #query-as-the-default-value-or-in-annotated }

Keep in mind that when using `Query` inside of `Annotated` you cannot use the `default` parameter for `Query`.

	var result User
	if DB.Where("").Where("").First(&result).Error != nil {
		t.Errorf("Should not raise any error if searching with empty strings")
	}

	result = User{}
	if DB.Where(&User{}).Where("name = ?", user.Name).First(&result).Error != nil {
		t.Errorf("Should not raise any error if searching with empty struct")
	}

	result = User{}

    * This doesn't refer to the file, nor to the code, it refers **specifically** to the thing that is being **executed** and managed by the operating system.
* Any program, any code, **can only do things** when it is being **executed**. So, when there's a **process running**.
* The process can be **terminated** (or "killed") by you, or by the operating system. At that point, it stops running/being executed, and it can **no longer do things**.

	var user1, user2, user3, user4, user5, user6 User
	if err := DB.Where(&User{Name: "find or init", Age: 33}).FirstOrInit(&user1).Error; err != nil {
		t.Errorf("no error should happen when FirstOrInit, but got %v", err)
	}

	if user1.Name != "find or init" || user1.ID != 0 || user1.Age != 33 {
		t.Errorf("user should be initialized with search value")
	}

	DB.Where(User{Name: "find or init", Age: 33}).FirstOrInit(&user2)

## Where are Packages Installed { #where-are-packages-installed }

When you install Python, it creates some directories with some files in your computer.

Some of these directories are the ones in charge of having all the packages you install.

When you run:

<div class="termy">

```console

  }

  /**
   * Regression test for an edge case where closing response body in the HTTP engine doesn't release
   * the corresponding stream allocation. This test keeps those response bodies alive and reads
   * them after the redirect has completed. This forces a connection to not be reused where it would
   * be otherwise.
   *
   *
   * This test leaks a response body by not closing it.