# Background Tasks - `BackgroundTasks`

You can declare a parameter in a *path operation function* or dependency function with the type `BackgroundTasks`, and then you can use it to schedule the execution of background tasks after the response is sent.

You can import it directly from `fastapi`:

```python
from fastapi import BackgroundTasks
```

 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.execution;

import javax.inject.Named;
import javax.inject.Singleton;

import java.io.IOException;
import java.io.Reader;
import java.io.Writer;
import java.nio.file.Files;
import java.nio.file.Path;

import java.util.Set;

import org.apache.maven.MavenExecutionException;
import org.apache.maven.execution.MavenExecutionRequest;
import org.apache.maven.project.MavenProject;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Utility class to extract {@link MavenProject} from the project graph during the execution phase based on optional or
 * required selectors.
 */
public final class ProjectSelector {

from starlette import status as status

from .applications import FastAPI as FastAPI
from .background import BackgroundTasks as BackgroundTasks
from .datastructures import UploadFile as UploadFile
from .exceptions import HTTPException as HTTPException
from .exceptions import WebSocketException as WebSocketException
from .param_functions import Body as Body
from .param_functions import Cookie as Cookie
from .param_functions import Depends as Depends

   * new value.
   *
   * <p><b>Warning:</b> this method silently converts checked exceptions to unchecked exceptions,
   * and should not be used with cache loaders which throw checked exceptions. In such cases use
   * {@link #get} instead.
   *
   * @throws UncheckedExecutionException if an exception was thrown while loading the value. (As

 * the License.
 */

package com.google.common.eventbus;


/**
 * Handler for exceptions thrown by event subscribers.
 *
 * @since 16.0
 */
@ElementTypesAreNonnullByDefault
public interface SubscriberExceptionHandler {
  /** Handles exceptions thrown by subscribers. */
  void handleException(Throwable exception, SubscriberExceptionContext context);

 *   <li>If a {@code Throwable} is thrown in the try block, no exceptions that occur when attempting
 *       to close resources will be thrown from the finally block. The throwable from the try block
 *       will be thrown.
 *   <li>If no exceptions or errors were thrown in the try block, the <i>first</i> exception thrown
 *       by an attempt to close a resource will be thrown.

<p>
The number of map elements is called its length.
For a map <code>m</code>, it can be discovered using the
built-in function <a href="#Length_and_capacity"><code>len</code></a>
and may change during execution. Elements may be added during execution
using <a href="#Assignments">assignments</a> and retrieved with
<a href="#Index_expressions">index expressions</a>; they may be removed with the

Auf die gleiche Weise könnten Sie im Exit-Code nach dem `yield` eine `HTTPException` oder ähnliches auslösen.

/// tip | "Tipp"

 *       so) before returning from the method. The {@code joinPool} method can be used to do this
 *       when using Executors.
 * </ol>
 *
 * <p><b>Other notes</b>
 *
 * <ul>
 *   <li>Usually, there is one testcase method per JSR166 method covering "normal" operation, and
 *       then as many exception-testing methods as there are exceptions the method can throw.