It is imported/included directly into FastAPI so that you can import it from `fastapi` and avoid accidentally importing the alternative `BackgroundTask` (without the `s` at the end) from `starlette.background`.

  }

  private void readObject(ObjectInputStream stream) throws InvalidObjectException {
    throw new InvalidObjectException("Use SerializedForm");
  }

  /** Serialized form of the map, to avoid serializing the constraint. */
  private static final class SerializedForm<B extends @Nullable Object> implements Serializable {
    private final Map<Class<? extends @NonNull B>, B> backingMap;

Various components described in Config Ingestion can trigger a Config Update. These are batched up ("debounced"), to avoid excessive activity when many changes happen in succession, and eventually enqueued in the Push Queue.

    }
    return Iterators.addAll(addTo, checkNotNull(elementsToAdd).iterator());
  }

  /**
   * Returns the number of elements in the specified iterable that equal the specified object. This
   * implementation avoids a full iteration when the iterable is a {@link Multiset} or {@link Set}.
   *
   * <p><b>Java 8+ users:</b> In most cases, the {@code Stream} equivalent of this method is {@code

              if (workerRunningState == RUNNING) {
                // Don't want to have two workers pulling from the queue.
                return;
              } else {
                // Increment the run counter to avoid the ABA problem of a submitter marking the
                // thread as QUEUED after it already ran and exhausted the queue before returning
                // from execute().
                workerRunCount++;

              if (workerRunningState == RUNNING) {
                // Don't want to have two workers pulling from the queue.
                return;
              } else {
                // Increment the run counter to avoid the ABA problem of a submitter marking the
                // thread as QUEUED after it already ran and exhausted the queue before returning
                // from execute().
                workerRunCount++;

func preloadEntryPoint(db *gorm.DB, joins []string, relationships *schema.Relationships, preloads map[string][]interface{}, associationsConds []interface{}) error {
	preloadMap := parsePreloadMap(db.Statement.Schema, preloads)

	// avoid random traversal of the map
	preloadNames := make([]string, 0, len(preloadMap))
	for key := range preloadMap {
		preloadNames = append(preloadNames, key)
	}
	sort.Strings(preloadNames)

object file at the beginning of any name starting with a period:
in an assembly source file within the math/rand package implementation,
the package's Int function can be referred to as <code>·Int</code>.
This convention avoids the need to hard-code a package's import path in its
own source code, making it easier to move the code from one location to another.
</p>

<h3 id="directives">Directives</h3>

<p>

   * while {@code ImmutableSortedSet.of(s)} returns an {@code ImmutableSortedSet<Set<String>>}
   * containing one element (the given set itself).
   *
   * <p>Despite the method name, this method attempts to avoid actually copying the data when it is
   * safe to do so. The exact circumstances under which a copy will or will not be performed are
   * undocumented and subject to change.
   *

      verifyHostname(hostname, it)
    }
  }

  /**
   * This is like [toLowerCase] except that it does nothing if this contains any non-ASCII
   * characters. We want to avoid lower casing special chars like U+212A (Kelvin symbol) because
   * they can return ASCII characters that match real hostnames.
   */
  private fun String.asciiToLowercase(): String {
    return when {