* be used.
 * <p>
 * This interface provides methods for logging messages at different severity levels
 * and supports logging with or without associated exceptions.
 *
 * @since 4.0.0
 */
@Experimental
public interface Logger {

    /**
     * Represents the severity levels for log messages.
     */
    enum Level {
        DEBUG,
        INFO,
        WARN,
        ERROR
    }

    // optimistically fill index position with elements from lower levels,
    // moving the hole down. In most cases this reduces the number of
    // comparisons with toTrickle, but in some cases we will need to bubble it
    // all the way up again.
    int vacated = heap.fillHoleAt(index);
    // Try to see if toTrickle can be bubbled up min levels.
    int bubbledTo = heap.bubbleUpAlternatingLevels(vacated, toTrickle);

 *       <ul>
 *         <li>2 levels: average of 64ns per lock()/unlock()
 *         <li>3 levels: average of 77ns per lock()/unlock()
 *         <li>4 levels: average of 99ns per lock()/unlock()
 *         <li>5 levels: average of 103ns per lock()/unlock()
 *         <li>10 levels: average of 184ns per lock()/unlock()
 *         <li>20 levels: average of 393ns per lock()/unlock()
 *       </ul>
 * </ul>

  @Override public void log(String message) {
    Timber.tag("OkHttp").d(message);
  }
});
```

**Warning**: The logs generated by this interceptor when using the `HEADERS` or `BODY` levels have
the potential to leak sensitive information such as "Authorization" or "Cookie" headers and the
contents of request and response bodies. This data should only be logged in a controlled way or in
a non-production environment.

 *       <ul>
 *         <li>2 levels: average of 64ns per lock()/unlock()
 *         <li>3 levels: average of 77ns per lock()/unlock()
 *         <li>4 levels: average of 99ns per lock()/unlock()
 *         <li>5 levels: average of 103ns per lock()/unlock()
 *         <li>10 levels: average of 184ns per lock()/unlock()
 *         <li>20 levels: average of 393ns per lock()/unlock()
 *       </ul>
 * </ul>

    logger: String,
    tag: String,
  ) {
    val logger = Logger.getLogger(logger)
    if (configuredLoggers.add(logger)) {
      logger.useParentHandlers = false
      // log based on levels at startup to avoid logging each frame
      logger.level =
        when {
          Log.isLoggable(tag, Log.DEBUG) -> Level.FINE
          Log.isLoggable(tag, Log.INFO) -> Level.INFO
          else -> Level.WARNING

            .replaceAll('###', '.*?')
    }
}

static String writeFilterPreset(Project project) {
    def preset = project.providers.gradleProperty('bin.cmp.report.severity.filter').getOrElse('All levels')
    return """<input id="filter-preset" type="hidden" value="$preset" />"""

 * with proper error context and recovery information.
 */
public class SmbException extends CIFSException {

    private static final long serialVersionUID = 1L;

    /**
     * Error severity levels
     */
    public enum Severity {
        RECOVERABLE, // Can retry the operation
        TRANSIENT, // Temporary error, retry after delay
        PERMANENT, // Operation cannot succeed

## Dependency Injection { #dependency-injection }

Using `BackgroundTasks` also works with the dependency injection system, you can declare a parameter of type `BackgroundTasks` at multiple levels: in a *path operation function*, in a dependency (dependable), in a sub-dependency, etc.

## **FastAPI**'s `OAuth2PasswordBearer` { #fastapis-oauth2passwordbearer }

**FastAPI** provides several tools, at different levels of abstraction, to implement these security features.

In this example we are going to use **OAuth2**, with the **Password** flow, using a **Bearer** token. We do that using the `OAuth2PasswordBearer` class.

/// info