OkHttp is **not** source-compatible for Kotlin callers, but upgrading should be automatic thanks to
Kotlin’s powerful deprecation features. Most developers should be able to use IntelliJ’s _Code
Cleanup_ for a safe and fast upgrade.


Backwards-Incompatible Changes
------------------------------

#### OkHttpClient final methods

`OkHttpClient` has 26 accessors like `interceptors()` and `writeTimeoutMillis()` that were non-final

   * dummy version.
   *
   * @throws UnsupportedOperationException always
   * @deprecated <b>Pass a parameter of type {@code Comparable} to use {@link
   *     ImmutableSortedSet#of(Comparable)}.</b>
   */
  @DoNotCall("Pass a parameter of type Comparable")
  @Deprecated
  public static <E> ImmutableSortedSet<E> of(E e1) {
    throw new UnsupportedOperationException();
  }

   * the two sets. If you have reason to believe one of your sets will generally be smaller than the
   * other, pass it first. Unfortunately, since this method sets the generic type of the returned
   * set based on the type of the first set passed, this could in rare cases force you to make a
   * cast, for example:
   *
   * {@snippet :
   * Set<Object> aFewBadObjects = ...
   * Set<String> manyBadStrings = ...
   *

     *
     * @return success count
     */
    public int getSuccessCount() {
        return successCount.get();
    }

    /**
     * Get time since last state change
     *
     * @return milliseconds since last state change
     */
    public long getTimeSinceLastStateChange() {
        return System.currentTimeMillis() - lastStateChangeTime.get();
    }

    /**

  public final @Nullable V getOrDefault(@Nullable Object key, @Nullable V defaultValue) {
    /*
     * Even though it's weird to pass a defaultValue that is null, some callers do so. Those who
     * pass a literal "null" should probably just use `get`, but I would expect other callers to
     * pass an expression that *might* be null. This could happen with:
     *
     * - a `getFooOrDefault(@Nullable Foo defaultValue)` method that returns

   */

  /*
   * These generators also rely on consecutive integer inputs (not necessarily in order, but no
   * holes).
   */

  // SetCreationTester has some tests that pass in duplicates. Dedup them.
  private static <E extends Comparable<? super E>> SortedSet<E> nullCheckedTreeSet(E[] elements) {
    SortedSet<E> set = newTreeSet();
    for (E element : elements) {

```

Digamos que ahora el archivo `main.py` con tu aplicación de **FastAPI** tiene algunas otras **path operations**.

Tiene una operación `GET` que podría devolver un error.

Tiene una operación `POST` que podría devolver varios errores.

Ambas *path operations* requieren un `X-Token` header.

//// tab | Python 3.10+

```Python
{!> ../../docs_src/app_testing/app_b_an_py310/main.py!}
```

////

  /** The HTTP {@code If-Unmodified-Since} header field name. */
  public static final String IF_UNMODIFIED_SINCE = "If-Unmodified-Since";

  /** The HTTP {@code Last-Event-ID} header field name. */
  public static final String LAST_EVENT_ID = "Last-Event-ID";

  /** The HTTP {@code Max-Forwards} header field name. */
  public static final String MAX_FORWARDS = "Max-Forwards";

   */

  /*
   * These generators also rely on consecutive integer inputs (not necessarily in order, but no
   * holes).
   */

  // SetCreationTester has some tests that pass in duplicates. Dedup them.
  private static <E extends Comparable<? super E>> SortedSet<E> nullCheckedTreeSet(E[] elements) {
    SortedSet<E> set = newTreeSet();
    for (E element : elements) {

   * table to be a view, but it means that the function will be applied many times for bulk
   * operations like {@link Table#containsValue} and {@code Table.toString()}. For this to perform
   * well, {@code function} should be fast. To avoid lazy evaluation when the returned table doesn't
   * need to be a view, copy the returned table into a new table of your choosing.
   *
   * @since 10.0
   */
  public static <