public Set<K> keySet() {
      /*
       * We can't use StandardKeySet, as NavigableMapTestSuiteBuilder assumes that our keySet is a
       * NavigableSet. We test StandardKeySet in the superclass, so it's still covered.
       */
      return navigableKeySet();
    }

    @Override
    public Collection<V> values() {
      return new StandardValues();
    }

    @Override
    public String toString() {

			return err
		}
		if w.reuseBlocks || o.reusable {
			metaDataPoolPut(o.metadata)
		}
	}

	return nil
}

// stream entries to the output.
// The returned channel should be closed when done.
// Any error is reported when closing the metacacheWriter.
func (w *metacacheWriter) stream() (chan<- metaCacheEntry, error) {
	if w.creator != nil {
		err := w.creator()
		w.creator = nil

## Development Information

### Get Source Code

1. Clone Fess's repository:
    ```
    $ cd ~/workspace
    $ git clone https://github.com/codelibs/fess.git
    ```
    
2. Import the cloned repository as a [Maven](https://maven.apache.org/) project on [Eclipse](https://www.eclipse.org/eclipseide/) or another IDE.

### Setup for OpenSearch Plugins

Run antrun:run to download plugins into the plugins directory:

        // Test the cloning behavior with both null and non-null cached subjects
        if (first != null) {
            // If we got a valid subject, test that it's properly cached and cloned
            Subject cachedOrig = orig.getSubject();
            assertNotNull(cachedOrig);

            // Cached subject is copied and visible via getSubject()
            Subject copySubj = copy.getSubject();

   * due to any of:
   *
   *  * A stale connection. The request was made on a reused connection and that reused connection
   *    has since been closed by the server.
   *  * A client timeout (HTTP 408).
   *  * A authorization challenge (HTTP 401 and 407) that is satisfied by the [Authenticator].
   *  * A retryable server failure (HTTP 503 with a `Retry-After: 0` response header).

     * clone. The only requirement is that invocations of {@link #addRepository(Repository)} on the clone do not affect
     * the state of the original resolver and vice versa.
     *
     * @return The cloned resolver, never {@code null}.
     */
    ModelResolver newCopy();

	// 		// connection. 5 minutes is sufficient time for any idle connection.
	// 		trhttp2.ReadIdleTimeout = 5 * time.Minute
	// 		// PingTimeout is the timeout after which the connection will be closed
	// 		// if a response to Ping is not received.
	// 		trhttp2.PingTimeout = dialTimeout
	// 		// DisableCompression, if true, prevents the Transport from
	// 		// requesting compression with an "Accept-Encoding: gzip"

	// responses from the remote server.
	// Channel will be closed after error or when remote closes.
	// responses *must* be read to either an error is returned or the channel is closed.
	responses *Stream
	newResp   func() Resp

	// Requests sent to the server.
	// If the handler is defined with 0 incoming capacity this will be nil.
	// Channel *must* be closed to signal the end of the stream.

    operation ->> dep_func: Return from path operation
    Note over dep_func: Run code after yield
    Note over dep_func: ✅ Dependency closed
    dep_func ->> client: Send response to client
    Note over client: Response sent
    Note over dep_req: Run code after yield
    Note over dep_req: ✅ Dependency closed
```

    operation ->> dep_func: Return from path operation
    Note over dep_func: Run code after yield
    Note over dep_func: ✅ Dependency closed
    dep_func ->> client: Send response to client
    Note over client: Response sent
    Note over dep_req: Run code after yield
    Note over dep_req: ✅ Dependency closed
```