is widely used on most Java projects within Google, and widely used by many
other companies as well.



Guava comes in two flavors:

*   The JRE flavor requires JDK 1.8 or higher.
*   If you need support for Android, use
    [the Android flavor](https://github.com/google/guava/wiki/Android). You can
    find the Android Guava source in the [`android` directory].

    return this;
  }

  /**
   * Advances the ticker value by {@code duration}.
   *
   * @since 33.1.0 (but since 28.0 in the JRE <a
   *     href="https://github.com/google/guava#guava-google-core-libraries-for-java">flavor</a>)
   */
  @GwtIncompatible
  @J2ktIncompatible
  @CanIgnoreReturnValue
  @IgnoreJRERequirement // TODO: b/288085449 - Remove this once we use library-desugaring scents.

   * writeLines(lines, System.getProperty("line.separator"))}.
   *
   * @throws IOException if an I/O error occurs while writing to this sink
   * @since 33.4.0 (but since 22.0 in the JRE flavor)
   */
  @IgnoreJRERequirement // Users will use this only if they're already using Stream.
  public void writeLines(Stream<? extends CharSequence> lines) throws IOException {
    writeLines(lines, LINE_SEPARATOR.value());

/**
 * Options for use with recursive delete methods ({@link MoreFiles#deleteRecursively} and {@link
 * MoreFiles#deleteDirectoryContents}).
 *
 * @since 33.4.0 (but since 21.0 in the JRE flavor)
 * @author Colin Decker
 */
@J2ktIncompatible
@GwtIncompatible
@J2ObjCIncompatible // java.nio.file
public enum RecursiveDeleteOption {
  /**

 * SecureDirectoryStream} is not supported).
 *
 * <p>{@link RecursiveDeleteOption#ALLOW_INSECURE} can be used to force the recursive delete method
 * to proceed anyway.
 *
 * @since 33.4.0 (but since 21.0 in the JRE flavor)
 * @author Colin Decker
 */
@J2ktIncompatible
@GwtIncompatible
@J2ObjCIncompatible // java.nio.file
// Users are unlikely to use this unless they're already interacting with MoreFiles and Path.
@IgnoreJRERequirement

  private final TypeToken<?> type;
  private final ImmutableList<Annotation> annotations;

  /**
   * An {@code AnnotatedType} instance, or {@code null} under Android VMs (possible only when using
   * the Android flavor of Guava). The field is declared with a type of {@code Object} to avoid
   * compatibility problems on Android VMs. The corresponding accessor method, however, can have the

  /*
   * The mainline copy of ImmutableMapValues doesn't produce this serialized form anymore, though
   * the backport does. For now, we're keeping the class declaration in *both* flavors so that both
   * flavors can read old data or data from the other flavor. However, we strongly discourage
   * relying on this, as we have made incompatible changes to serialized forms in the past and

   *   ForwardingSet does not forward `default` methods, as discussed in its Javadoc.
   */

  // Currently, we don't include stream() and spliterator() for our classes in the Android flavor.

  @Override
  public boolean remove(@Nullable Object o) {
    assertTrue(Thread.holdsLock(mutex));
    return super.remove(o);
  }

  @Override
  public boolean removeAll(Collection<?> c) {

  /*
   * The mainline copy of ImmutableMapValues doesn't produce this serialized form anymore, though
   * the backport does. For now, we're keeping the class declaration in *both* flavors so that both
   * flavors can read old data or data from the other flavor. However, we strongly discourage
   * relying on this, as we have made incompatible changes to serialized forms in the past and

So, even with the code above that doesn't use Pydantic explicitly, FastAPI is using Pydantic to convert those standard dataclasses to Pydantic's own flavor of dataclasses.

And of course, it supports the same:

* data validation
* data serialization
* data documentation, etc.