LogStream.setInstance(stream1);
        LogStream instance1 = LogStream.getInstance();

        LogStream.setInstance(stream2);
        LogStream instance2 = LogStream.getInstance();

        // Each setInstance should create a new LogStream
        assertNotNull(instance1);
        assertNotNull(instance2);

Russ Cox <******@****.***> 1410149331 -0400

 *
 * ## Connection Reuse
 *
 * Each connection can carry a varying number of streams, depending on the underlying protocol being
 * used. HTTP/1.x connections can carry either zero or one streams. HTTP/2 connections can carry any
 * number of streams, dynamically configured with `SETTINGS_MAX_CONCURRENT_STREAMS`. A connection
 * currently carrying zero streams is an idle stream. We keep it alive because reusing an existing

 */
interface PushObserver {
  /**
   * Describes the request that the server intends to push a response for.
   *
   * @param streamId server-initiated stream ID: an even number.
   * @param requestHeaders minimally includes `:method`, `:scheme`, `:authority`,
   * and `:path`.
   */
  fun onRequest(
    streamId: Int,
    requestHeaders: List<Header>,
  ): Boolean

  /**

     * @param map the map to create a stream from; if {@code null}, an empty stream is returned
     * @return a {@link StreamOf} containing the entries of the map, or an empty stream if the map is {@code null}
     */
    public static <K, V> StreamOf<Map.Entry<K, V>> stream(final Map<K, V> map) {
        return new StreamOf<>(() -> map != null ? map.entrySet().stream() : Collections.<K, V> emptyMap().entrySet().stream());
    }

  override fun data(
    inFinished: Boolean,
    streamId: Int,
    source: BufferedSource,
    length: Int,
  ) {
    fail("")
  }

  override fun headers(
    inFinished: Boolean,
    streamId: Int,
    associatedStreamId: Int,
    headerBlock: List<Header>,
  ) {
    fail("")
  }

  override fun rstStream(
    streamId: Int,
    errorCode: ErrorCode,
  ) {
    fail("")
  }

#### Framed protocols

Framed protocols like http/2 don't lend themselves to blocking APIs. Each application-layer thread wants to do blocking I/O for a specific stream, but the streams are multiplexed on the socket. You can't just talk to the socket, you need to cooperate with the other application-layer threads that you're sharing it with.

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.auth;

import static org.codelibs.core.stream.StreamUtil.stream;

import org.apache.commons.lang3.ArrayUtils;
import org.codelibs.core.stream.StreamUtil.StreamOf;
import org.codelibs.fess.auth.chain.AuthenticationChain;
import org.codelibs.fess.opensearch.user.exentity.User;

/**

/**
 * MimeTypeHelper provides methods to determine the content type of a given input stream or file.
 * It allows content type detection based on the stream's content and/or filename.
 */
public interface MimeTypeHelper {
    /**
     * Determines the content type of the given input stream and filename.
     * @param is the input stream to analyze
     * @param filename the filename to help determine the content type

   *
   * ```
   * direction streamID length type flags
   * ```
   *
   * Where direction is `<<` for inbound and `>>` for outbound.
   *
   * For example, the following would indicate a HEAD request sent from the client.
   * ```
   * `<< 0x0000000f    12 HEADERS       END_HEADERS|END_STREAM
   * ```
   */
  fun frameLog(
    inbound: Boolean,
    streamId: Int,
    length: Int,
    type: Int,