// Cache implementors may want to catch it but should not need to be able to throw it.
    UnsupportedLoadingOperationException() {}
  }

  /**
   * Thrown to indicate that an invalid response was returned from a call to {@link CacheLoader}.
   *
   * @since 11.0
   */
  public static final class InvalidCacheLoadException extends RuntimeException {
    public InvalidCacheLoadException(String message) {

  }

  /**
   * A predicate that is expected to return true subsequent to finalization, that is, one
   * of the following actions taken by the garbage collector when performing a full collection in
   * response to {@link System#gc()}:
   *
   * <ul>
   *   <li>invoking the {@code finalize} methods of unreachable objects
   *   <li>clearing weak references to unreachable referents

     * contrast to the "V?" type that we're using. As a result, Kotlin sees a conflict between the
     * nullness annotations in ImmutableMap and those in its own Map type. In response, it considers
     * the parameter and return type both to be platform types. As a result, Kotlin permits calls
     * that can lead to NullPointerException. That's unfortunate. But hopefully most Kotlin callers

   * SoftReference} (by default, strong references are used). Softly-referenced objects will be
   * garbage-collected in a <i>globally</i> least-recently-used manner, in response to memory
   * demand.
   *
   * <p><b>Warning:</b> in most circumstances it is better to set a per-cache {@linkplain
   * #maximumSize(long) maximum size} instead of using soft references. You should only use this

    @Override
    public void failed(State from, Throwable failure) {
      ServiceManagerState state = this.state.get();
      if (state != null) {
        // Log before the transition, so that if the process exits in response to server failure,
        // there is a higher likelihood that the cause will be in the logs.
        boolean log = !(service instanceof NoOpService);
        if (log) {
          logger
              .get()

   * SoftReference} (by default, strong references are used). Softly-referenced objects will be
   * garbage-collected in a <i>globally</i> least-recently-used manner, in response to memory
   * demand.
   *
   * <p><b>Warning:</b> in most circumstances it is better to set a per-cache {@linkplain
   * #maximumSize(long) maximum size} instead of using soft references. You should only use this

        }
        return instance;
      }
    }
    throw new IllegalArgumentException(
        "No appropriate constructor for exception of type "
            + exceptionClass
            + " in response to chained exception",
        cause);
  }

  private static <X extends Exception> List<Constructor<X>> preferringStringsThenThrowables(
      List<Constructor<X>> constructors) {

 * </ul>
 *
 * @author Kurt Alfred Kluever
 * @since 11.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public final class HttpHeaders {
  private HttpHeaders() {}

  // HTTP Request and Response header fields

  /** The HTTP {@code Cache-Control} header field name. */
  public static final String CACHE_CONTROL = "Cache-Control";
  /** The HTTP {@code Content-Length} header field name. */