return stream.readInt();
  }

  /**
   * Stores the contents of a map in an output stream, as part of serialization. It does not support
   * concurrent maps whose content may change while the method is running.
   *
   * <p>The serialized output consists of the number of entries, first key, first value, second key,
   * second value, and so on.
   */

 * stored bytes exceeds the limit, the cache will remove entries in the background until the limit
 * is satisfied. The limit is not strict: the cache may temporarily exceed it while waiting for
 * files to be deleted. The limit does not include filesystem overhead or the cache journal so
 * space-sensitive applications should set a conservative limit.
 *

     * @return {@link List} $lt; {@link ArtifactVersion} >
     * @throws ArtifactMetadataRetrievalException
     *          in case of error while retrieving repository metadata from the repository.
     */
    List<ArtifactVersion> retrieveAvailableVersions(
            Artifact artifact, ArtifactRepository localRepository, List<ArtifactRepository> remoteRepositories)

 * and adds them as child URLs to be crawled.
 *
 * <p>
 * This class uses a {@link SitemapsHelper} to parse the sitemap XML or text.
 * It then iterates through the sitemaps in the SitemapSet, extracts the URL
 * from each sitemap, and creates a new {@link RequestData} object for each URL.
 * These RequestData objects are added to a set of child URLs, which are then

    assertFullyRead(reader);

    // read in chunks to fixed array
    reader = new CharSequenceReader(charSequence);
    buf = new char[5];
    StringBuilder builder = new StringBuilder();
    int read;
    while ((read = reader.read(buf, 0, buf.length)) != -1) {
      builder.append(buf, 0, read);
    }
    assertEquals(expected, builder.toString());
    assertFullyRead(reader);

    // read all to one CharBuffer

      return -1;
    }
    List<?> list = (List<?>) o;
    if (list.size() != axes.size()) {
      return -1;
    }
    ListIterator<?> itr = list.listIterator();
    int computedIndex = 0;
    while (itr.hasNext()) {
      int axisIndex = itr.nextIndex();
      int elemIndex = axes.get(axisIndex).indexOf(itr.next());
      if (elemIndex == -1) {
        return -1;
      }

<img src="/img/async/concurrent-burgers/concurrent-burgers-04.png" class="illustration">

While you are waiting, you go with your crush and pick a table, you sit and talk with your crush for a long time (as your burgers are very fancy and take some time to prepare).

As you are sitting at the table with your crush, while you wait for the burgers, you can spend that time admiring how awesome, cute and smart your crush is ✨😍✨.

#### Http2Writer

Socket writes are guarded by the Http2Writer. Only one stream can write at a time so that messages are not interleaved. Writes are either made by application-layer threads or the do-stuff-later pool.

### Holding multiple locks

            assertEquals(maxCount, dataService.getCount(sessionId2));

            UrlQueue urlQueue;
            while ((urlQueue = urlQueueService.poll(sessionId1)) != null) {
                assertTrue(urlQueue.getUrl().startsWith(url1));
            }
            while ((urlQueue = urlQueueService.poll(sessionId2)) != null) {
                assertTrue(urlQueue.getUrl().startsWith(url2));
            }

    @Override
    public Hasher putBytes(ByteBuffer buffer) {
      ByteOrder bo = buffer.order();
      buffer.order(ByteOrder.LITTLE_ENDIAN);
      while (buffer.remaining() >= 4) {
        putInt(buffer.getInt());
      }
      while (buffer.hasRemaining()) {
        putByte(buffer.get());
      }
      buffer.order(bo);
      return this;
    }

    @CanIgnoreReturnValue
    @Override