}

// TODO(vnvo2409): Add more tests from `python/ops/gradient_checker_v2_test.py`.
// These tests should not be confused with `[*]_grad_test` which compare the
// result of `gradient_checker` and `[*]_grad`. The tests here test the
// functionality of `gradient_checker` by comparing the result with expected
// manual user-provided gradients.
class GradientCheckerTest
    : public ::testing::TestWithParam<std::tuple<const char*, bool, bool>> {

How to contribute
=================

Thank you so much for wanting to contribute to Guava! Here are a few important
things you should know about contributing:

1.  API changes require discussion, use cases, etc. Code comes later.
2.  Pull requests are great for small fixes for bugs, documentation, etc.
3.  Pull requests are not merged directly into the master branch.
4.  Code contributions require signing a Google CLA.

API changes
-----------

           * Technically this loop not guaranteed to terminate, so theoretically (extremely
           * unlikely) this thread might starve, but even then, there is always going to be another
           * thread doing progress here.
           */
        }
      }
    }
  }

  /**
   * Returns a function that delegates to the {@link Interner#intern} method of the given interner.
   *
   * @since 8.0
   */

            modelValueSource2 = new ProblemDetectingValueSource(modelValueSource2, "", "project.", problems);
        }

        // NOTE: Order counts here!
        List<ValueSource> valueSources = new ArrayList<>(9);

        if (projectDir != null) {
            ValueSource basedirValueSource = new PrefixedValueSourceWrapper(

But when you want to make a query parameter required, you can just not declare any default value:

{* ../../docs_src/query_params/tutorial005_py310.py hl[6:7] *}

Here the query parameter `needy` is a required query parameter of type `str`.

If you open in your browser a URL like:

```
http://127.0.0.1:8000/items/foo-item
```

func (initialSnapShot LeakDetect) CompareCurrentSnapshot() []string {
	var stackDiff []string
	for _, g := range pickRelevantGoroutines() {
		// Identify the Go routines those were not present in the initial snapshot.
		// In other words a stack diff.
		if !initialSnapShot.relevantRoutines[g] {
			stackDiff = append(stackDiff, g)
		}
	}
	return stackDiff
}

 * ServerSocket} is closed even if the {@code MyServer} object is garbage-collected without calling
 * its {@code close} method. You could use a finalizer to accomplish this, but that has a
 * number of well-known problems. Here is how you might use this class instead:
 *
 * {@snippet :
 * public class MyServer implements Closeable {
 *   private static final FinalizableReferenceQueue frq = new FinalizableReferenceQueue();

But now, having `Query(max_length=50)` inside of `Annotated`, we are telling FastAPI that we want it to have **additional validation** for this value, we want it to have maximum 50 characters. 😎

/// tip

Here we are using `Query()` because this is a **query parameter**. Later we will see others like `Path()`, `Body()`, `Header()`, and `Cookie()`, that also accept the same arguments as `Query()`.

///

FastAPI will now:

* `tags: List[str] = []` has a default of an empty list: `[]`.

but you might want to omit them from the result if they were not actually stored.

For example, if you have models with many optional attributes in a NoSQL database, but you don't want to send very long JSON responses full of default values.

### Use the `response_model_exclude_unset` parameter { #use-the-response-model-exclude-unset-parameter }

```console
$ fastapi dev

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

Então, vá para a interface `/docs`, você verá que o **FastAPI** está usando esses **modelos** para **documentar** a API, e ele também os usará para **serializar** e **validar** os dados.

<div class="screenshot">
<img src="/img/tutorial/sql-databases/image01.png">
</div>