/**
   * @param eventBus The {@link EventBus} that handled the event and the subscriber. Useful for
   *     broadcasting a new event based on the error.
   * @param event The event object that caused the subscriber to throw.
   * @param subscriber The source subscriber context.
   * @param subscriberMethod the subscribed method.
   */
  SubscriberExceptionContext(

```Python
from starlette.exceptions import HTTPException as StarletteHTTPException
```

### Reuse **FastAPI**'s exception handlers

If you want to use the exception along with the same default exception handlers from  **FastAPI**, you can import and reuse the default exception handlers from `fastapi.exception_handlers`:

```Python hl_lines="2-5  15  21"

{* ../../docs_src/custom_docs_ui/tutorial001.py hl[8] *}

### Include the custom docs

Now you can create the *path operations* for the custom docs.

You can reuse FastAPI's internal functions to create the HTML pages for the docs, and pass them the needed arguments:

     * value is undefined.
     *
     * @return The location of the problem, never {@code null}.
     */
    String getLocation();

    /**
     * Gets the exception that caused this problem (if any).
     *
     * @return The exception that caused this problem or {@code null} if not applicable.
     */
    Exception getException();

    /**
     * Gets the message that describes this problem.
     *

      e: IOException?,
    )

    fun noNewExchanges()

    fun cancel()
  }

  companion object {
    /**
     * The timeout to use while discarding a stream of input data. Since this is used for connection
     * reuse, this timeout should be significantly less than the time it takes to establish a new
     * connection.
     */
    const val DISCARD_STREAM_TIMEOUT_MILLIS = 100
  }

        for (final Throwable t : throwables) {
            s.println("Caused " + count + ":");
            t.printStackTrace(s);
            count++;
        }
    }

    @Override
    public void printStackTrace(final PrintWriter s) {
        super.printStackTrace(s);

        int count = 1;
        for (final Throwable t : throwables) {
            s.println("Caused " + count + ":");
            t.printStackTrace(s);

          annotationClass.getDeclaringClass(),
          returnType.getComponentType());
    }
  }

  // This is public so that tests for Feature enums we haven't yet imagined
  // can reuse it.
  public static <E extends Enum<?> & Feature<?>> void assertGoodFeatureEnum(
      Class<E> featureEnumClass) {
    final Class<?>[] classes = featureEnumClass.getDeclaredClasses();

     * value is undefined.
     *
     * @return The location of the problem, never {@code null}.
     */
    String getLocation();

    /**
     * Gets the exception that caused this problem (if any).
     *
     * @return The exception that caused this problem or {@code null} if not applicable.
     */
    Exception getException();

    /**
     * Gets the message that describes this problem.
     *

          annotationClass.getDeclaringClass(),
          returnType.getComponentType());
    }
  }

  // This is public so that tests for Feature enums we haven't yet imagined
  // can reuse it.
  public static <E extends Enum<?> & Feature<?>> void assertGoodFeatureEnum(
      Class<E> featureEnumClass) {
    final Class<?>[] classes = featureEnumClass.getDeclaredClasses();

 *
 * <p>Invalid:
 *
 * <ul>
 *   <li>Expired: time expired (key/value may still be set)
 *   <li>Collected: key/value was partially collected, but not yet cleaned up
 *   <li>Unset: marked as unset, awaiting cleanup or reuse
 * </ul>
 */
@GwtIncompatible
@ElementTypesAreNonnullByDefault
interface ReferenceEntry<K, V> {
  /** Returns the value reference from this entry. */
  @CheckForNull
  ValueReference<K, V> getValueReference();