import java.util.TreeSet;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests operations on a NavigableSet. Can't be invoked directly; please
 * see {@code NavigableSetTestSuiteBuilder}.
 *
 * @author Jesse Wilson
 * @author Louis Wasserman
 */
@GwtIncompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")

import java.util.NavigableMap;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests operations on a NavigableMap. Can't be invoked directly; please
 * see {@code NavigableMapTestSuiteBuilder}.
 *
 * @author Jesse Wilson
 * @author Louis Wasserman
 */
@GwtIncompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")

 * methods. This class uses a single thread to execute the service; consider {@link AbstractService}
 * if you would like to manage any threading manually.
 *
 * @author Jesse Wilson
 * @since 1.0
 */
@GwtIncompatible
@J2ktIncompatible
public abstract class AbstractExecutionThreadService implements Service {
  /* use AbstractService for state management */
  private final Service delegate =

### El archivo de configuración

Proveniente del ejemplo anterior, tu archivo `config.py` podría verse como:

{* ../../docs_src/settings/app02/config.py hl[10] *}

Nota que ahora no creamos una instance por defecto `settings = Settings()`.

### El archivo principal de la app

Por supuesto, usarías las mismas ideas que leíste en [Acerca de las versiones de FastAPI](versions.md){.internal-link target=_blank} para establecer los rangos de versiones.

Por ejemplo, tu `requirements.txt` podría verse así:

```
fastapi[standard]>=0.113.0,<0.114.0
pydantic>=2.7.0,<3.0.0
```

Y normalmente instalarías esas dependencias de los paquetes con `pip`, por ejemplo:

<div class="termy">

```console

import java.util.concurrent.TimeoutException;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Unit test for {@link AbstractExecutionThreadService}.
 *
 * @author Jesse Wilson
 */
@NullUnmarked
public class AbstractExecutionThreadServiceTest extends TestCase {

  private final TearDownStack tearDownStack = new TearDownStack(true);

import java.util.TreeSet;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests operations on a NavigableSet. Can't be invoked directly; please
 * see {@code NavigableSetTestSuiteBuilder}.
 *
 * @author Jesse Wilson
 * @author Louis Wasserman
 */
@GwtIncompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")

 *
 * <p>Implementors of this interface are strongly encouraged to extend one of the abstract classes
 * in this package which implement this interface and make the threading and state management
 * easier.
 *
 * @author Jesse Wilson
 * @author Luke Sandberg
 * @since 9.0 (in 1.0 as {@code com.google.common.base.Service})
 */
@DoNotMock("Create an AbstractIdleService")
@J2ktIncompatible
@GwtIncompatible
public interface Service {
  /**

  `She can't explain it,' said the Gryphon hastily.  `Go on with
the next verse.'

  `But about his toes?' the Mock Turtle persisted.  `How COULD
he turn them out with his nose, you know?'

  `It's the first position in dancing.' Alice said; but was
dreadfully puzzled by the whole thing, and longed to change the
subject.

  `Go on with the next verse,' the Gryphon repeated impatiently:
`it begins "I passed by his garden."'

 * implementations exist for particular cases, like {@link ImmutableTable} views and hash flooding.
 * (This doc discusses {@link ImmutableMap} subclasses only for the JRE flavor; the Android flavor
 * differs.)
 *
 * @author Jesse Wilson
 * @author Kevin Bourrillion
 * @author Gregory Kick
 */
@GwtCompatible
final class RegularImmutableMap<K, V> extends ImmutableMap<K, V> {
  @SuppressWarnings("unchecked")