*     .add("x", 1)
   *     .add("y", null)
   *     .toString();
   * }
   *
   * <p>Note that in GWT, class names are often obfuscated.
   *
   * @param self the object to generate the string for (typically {@code this}), used only for its
   *     class name
   * @since 18.0 (since 2.0 as {@code Objects.toStringHelper()}).
   */
  public static ToStringHelper toStringHelper(Object self) {

/**
 * Utilities for collecting and validating tester requirements from annotations.
 *
 * @author George van den Driessche
 */
@GwtIncompatible
public final class FeatureUtil {
  /** A cache of annotated objects (typically a Class or Method) to its set of annotations. */
  private static final Map<AnnotatedElement, List<Annotation>> annotationCache = new HashMap<>();

import org.jspecify.annotations.Nullable;

/**
 * An {@link Escaper} that converts literal text into a format safe for inclusion in a particular
 * context (such as an XML document). Typically (but not always), the inverse process of
 * "unescaping" the text is performed automatically by the relevant parser.
 *
 * <p>For example, an XML escaper would convert the literal string {@code "Foo<Bar>"} into {@code

import org.jspecify.annotations.Nullable;

/**
 * An {@link Escaper} that converts literal text into a format safe for inclusion in a particular
 * context (such as an XML document). Typically (but not always), the inverse process of
 * "unescaping" the text is performed automatically by the relevant parser.
 *
 * <p>For example, an XML escaper would convert the literal string {@code "Foo<Bar>"} into {@code

   * [trailers], this doesn't block if the trailers are not immediately available, and instead
   * returns null.
   *
   * This will typically return null until [ResponseBody.source] has buffered the last byte of the
   * response body. Call `body.source().request(1024 * 1024)` to block until either that's done, or

            }
            return OptionalEntity.empty();
        });
    }

    /**
     * Gets the action response for the specified SSO response type.
     *
     * SPNEGO authentication typically doesn't require special response handling
     * for metadata or logout operations, so this method returns null.
     *
     * @param responseType The type of SSO response requested

   * network interceptors return.
   */
  internal var interceptorScopedExchange: Exchange? = null
    private set

  // These properties are guarded by `this`. They are typically only accessed by the thread executing
  // the call, but they may be accessed by other threads for duplex requests.

  /** True if this call still has a request body open. */
  private var requestBodyOpen = false

   *     .add("x", 1)
   *     .add("y", null)
   *     .toString();
   * }
   *
   * <p>Note that in GWT, class names are often obfuscated.
   *
   * @param self the object to generate the string for (typically {@code this}), used only for its
   *     class name
   * @since 18.0 (since 2.0 as {@code Objects.toStringHelper()}).
   */
  public static ToStringHelper toStringHelper(Object self) {

   * Supplier#get} on that supplier.
   *
   * <p>Prefer to use the method reference {@code Supplier::get} instead, though note that it is not
   * serializable unless you explicitly make it {@link Serializable}, typically by writing {@code
   * (Function<Supplier<T>, T> & Serializable) Supplier::get}.
   *
   * @since 8.0
   */
  public static <T extends @Nullable Object> Function<Supplier<T>, T> supplierFunction() {

     *     passed to {@code whenAllSucceed}, if that is the method you used to create this {@code
     *     FutureCombiner}). Even if you don't care about the value of the future, you should
     *     typically check whether it failed: See <a
     *     href="https://errorprone.info/bugpattern/FutureReturnValueIgnored">https://errorprone.info/bugpattern/FutureReturnValueIgnored</a>.
     */