* @param request the request to create a key for
     * @throws IOException if an I/O error occurs
     */
    protected abstract void makeKey(Request request) throws IOException;

    /**
     * Reads and returns the key of the next message without consuming it.
     *
     * @return the request key of the next message
     * @throws IOException if an I/O error occurs
     */
    protected abstract Request peekKey() throws IOException;

import java.util.Spliterator;
import java.util.Spliterators;
import java.util.function.LongConsumer;
import java.util.stream.LongStream;
import org.jspecify.annotations.Nullable;

/**
 * An immutable array of {@code long} values, with an API resembling {@link List}.
 *
 * <p>Advantages compared to {@code long[]}:
 *
 * <ul>
 *   <li>All the many well-known advantages of immutability (read <i>Effective Java</i>, third

You can define this *startup* and *shutdown* logic using the `lifespan` parameter of the `FastAPI` app, and a "context manager" (I'll show you what that is in a second).

Let's start with an example and then see it in detail.

We create an async function `lifespan()` with `yield` like this:

{* ../../docs_src/events/tutorial003_py310.py hl[16,19] *}

```JSON
{
  "detail": "Not authenticated"
}
```

### Inactive user { #inactive-user }

Now try with an inactive user, authenticate with:

User: `alice`

Password: `secret2`

And try to use the operation `GET` with the path `/users/me`.

You will get an "Inactive user" error, like:

```JSON
{

     */
    protected ArrayUtil() {
    }

    /**
     * Returns an array of {@literal boolean}.
     *
     * @param elements the elements of the array
     * @return the array
     */
    public static boolean[] asBooleanArray(final boolean... elements) {
        return elements;
    }

    /**
     * Returns an array of {@literal char}.
     *
     * @param elements the elements of the array

 * <p>When {@code post} is called, all registered subscribers for an event are run in sequence, so
 * subscribers should be reasonably quick. If an event may trigger an extended process (such as a
 * database load), spawn a thread or queue it for later. (For a convenient way to do this, use an
 * {@link AsyncEventBus}.)
 *
 * <h2>Subscriber Methods</h2>
 *
 * <p>Event subscriber methods must accept only one argument: the event.
 *

      this.node = node;
    }
  }

  /**
   * Determines whether an edge has already been used during traversal. In the directed case a cycle
   * is always detected before reusing an edge, so no special logic is required. In the undirected
   * case, we must take care not to "backtrack" over an edge (i.e. going from A to B and then going
   * from B to A).
   */

  // clients from directly destroying this object since it may manage its own
  // lifetime through ref counting. Thus clients MUST call Release() in order to
  // destroy an instance of this class.
  virtual void Release() = 0;

  // Creates an operation builder and ties it to this context.
  // The returned object can be used for setting operation's attributes,
  // adding inputs and finally executing (immediately or lazily as in tracing)

 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.codelibs.core.collection;

import java.util.Iterator;

import org.codelibs.core.exception.ClUnsupportedOperationException;

/**
 * An empty {@link Iterator}.
 *
 * @author higa

import org.jspecify.annotations.Nullable;

/**
 * An abstract implementation of {@link ListenableFuture}, intended for advanced users only. More
 * common ways to create a {@code ListenableFuture} include instantiating a {@link SettableFuture},
 * submitting a task to a {@link ListeningExecutorService}, and deriving a {@code Future} from an
 * existing one, typically using methods like {@link Futures#transform(ListenableFuture,