* annotated by {@link TestSubtype}.
 *
 * <p>These declaration methods rely on Java static type checking to make sure what we want to
 * assert as subtypes are really subtypes according to javac. For example:
 *
 * {@snippet :
 * class MySubtypeTests extends SubtypeTester {
 *   @TestSubtype(suppressGetSubtype = true, suppressGetSupertype = true)

 * annotated by {@link TestSubtype}.
 *
 * <p>These declaration methods rely on Java static type checking to make sure what we want to
 * assert as subtypes are really subtypes according to javac. For example:
 *
 * {@snippet :
 * class MySubtypeTests extends SubtypeTester {
 *   @TestSubtype(suppressGetSubtype = true, suppressGetSupertype = true)

     * it.
     */
    setResult(transformResult);
  }

  /** Template method for subtypes to actually run the transform. */
  @ForOverride
  @ParametricNullness
  abstract T doTransform(F function, @ParametricNullness I result) throws Exception;

  /** Template method for subtypes to actually set the result. */
  @ForOverride
  abstract void setResult(@ParametricNullness T result);

  @Override

     * it.
     */
    setResult(transformResult);
  }

  /** Template method for subtypes to actually run the transform. */
  @ForOverride
  @ParametricNullness
  abstract T doTransform(F function, @ParametricNullness I result) throws Exception;

  /** Template method for subtypes to actually set the result. */
  @ForOverride
  abstract void setResult(@ParametricNullness T result);

  @Override

import okhttp3.CallEvent.SatisfactionFailure
import okhttp3.CallEvent.SecureConnectEnd
import okhttp3.CallEvent.SecureConnectStart

/**
 * This accepts events as function calls on [EventListener], and publishes them as subtypes of
 * [CallEvent].
 */
class EventListenerAdapter : EventListener() {
  var listeners = listOf<(CallEvent) -> Unit>()

  private fun onEvent(listener: CallEvent) {
    for (function in listeners) {

The string will be checked to be a valid URL, and documented in JSON Schema / OpenAPI as such.

## Attributes with lists of submodels { #attributes-with-lists-of-submodels }

You can also use Pydantic models as subtypes of `list`, `set`, etc.:

{* ../../docs_src/body_nested_models/tutorial006_py310.py hl[18] *}

This will expect (convert, validate, document, etc.) a JSON body like:

```JSON hl_lines="11"
{

     * have the same nullness as E." Since we can't, we declare it to return nullable elements, and
     * we can override it in our non-null-guaranteeing subtypes to present a better signature to
     * their users.
     *
     * However, the checker *we* use has this special knowledge about `Collection.toArray()` anyway,

 * detailed at {@link ImmutableCollection}.
 *
 * <p><b>Warning:</b> avoid <i>direct</i> usage of {@link ImmutableMultimap} as a type (as with
 * {@link Multimap} itself). Prefer subtypes such as {@link ImmutableSetMultimap} or {@link
 * ImmutableListMultimap}, which have well-defined {@link #equals} semantics, thus avoiding a common
 * source of bugs and confusion.
 *

 * Tests our AtomicHelper fallback strategy in AggregateFutureState.
 *
 * <p>On different platforms AggregateFutureState uses different strategies for its core
 * synchronization primitives. The strategies are all implemented as subtypes of AtomicHelper and
 * the strategy is selected in the static initializer of AggregateFutureState. This is convenient
 * and performant but introduces some testing difficulties. This test exercises the two fallback
 * strategies.

/**
 * Tests our AtomicHelper fallback strategies in AbstractFuture.
 *
 * <p>On different platforms AbstractFuture uses different strategies for its core synchronization
 * primitives. The strategies are all implemented as subtypes of AtomicHelper and the strategy is
 * selected in the static initializer of AbstractFuture. This is convenient and performant but
 * introduces some testing difficulties. This test exercises the fallback strategies.
 *