}
          buffer.add(e);
          added++;
        }
      }
    } finally {
      if (interrupted) {
        Thread.currentThread().interrupt();
      }
    }
    return added;
  }

  /**
   * Returns a synchronized (thread-safe) queue backed by the specified queue. In order to guarantee
   * serial access, it is critical that <b>all</b> access to the backing queue is accomplished

/**
 * A Ticker whose value can be advanced programmatically in test.
 *
 * <p>The ticker can be configured so that the time is incremented whenever {@link #read} is called:
 * see {@link #setAutoIncrementStep}.
 *
 * <p>This class is thread-safe.
 *
 * @author Jige Yu
 * @since 10.0
 */
@ElementTypesAreNonnullByDefault
@GwtCompatible
public class FakeTicker extends Ticker {

        .build()
    val request = Request(server.url("/"))
    val response1 = client.newCall(request).execute()
    assertThat(response1.body.string()).isEqualTo("a")

    // Give the thread pool a chance to evict.
    Thread.sleep(500)
    val response2 = client.newCall(request).execute()
    assertThat(response2.body.string()).isEqualTo("b")
    assertThat(server.takeRequest().sequenceNumber).isEqualTo(0)

 * invoke methods, they invoke methods on the {@code ForwardingMultiset}.
 *
 * <p>The {@code standard} methods and any collection views they return are not guaranteed to be
 * thread-safe, even when all of the methods that they depend on are thread-safe.
 *
 * @author Kevin Bourrillion
 * @author Louis Wasserman
 * @since 2.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault

 * memorized and kept as long as supplier instance is kept open.
 * <p>
 * This class is not thread safe and must be used from one thread only, while the constructed {@link RepositorySystem}
 * is thread safe.
 * <p>
 * Important: Given the instance of supplier memorizes the supplier {@link RepositorySystem} instance it supplies,

    protected long maxAccessCount = Long.MAX_VALUE;

    protected long crawlingExecutionInterval = Constants.DEFAULT_CRAWLING_EXECUTION_INTERVAL;

    protected int indexUpdaterPriority = Thread.MAX_PRIORITY;

    protected int crawlerPriority = Thread.NORM_PRIORITY;

    protected final List<Crawler> crawlerList = Collections.synchronizedList(new ArrayList<>());

            if (!p.isAlive()) {
                return;
            }

            executed.set(true);

            if (logger.isDebugEnabled()) {
                logger.debug("Interrupting a stream thread.");
            }
            ist.interrupt();

            CommonPoolUtil.execute(() -> {
                try {
                    CloseableUtil.closeQuietly(p.getInputStream());

 * possibly run in another thread. That cause should itself be an {@code Error}; if not, use {@code
 * ExecutionException} or {@link UncheckedExecutionException}. This allows the client code to
 * continue to distinguish between exceptions and errors, even when they come from other threads.
 *
 * @author Chris Povirk
 * @since 10.0
 */
@GwtCompatible

        failureUrl.setErrorName(errorName);
        failureUrl.setErrorLog(getStackTrace(e));
        failureUrl.setLastAccessTime(ComponentUtil.getSystemHelper().getCurrentTimeAsLong());
        failureUrl.setThreadName(Thread.currentThread().getName());

        bhv.insertOrUpdate(failureUrl, op -> {
            op.setRefreshPolicy(Constants.TRUE);
        });
        return failureUrl;
    }

        }
    }

    // ===================================================================================================
    /**
     * Helper class to traverse graph. Required to make the containing method thread-safe
     * and yet use class level data to lessen stack usage in recursion
     */
    private class ClasspathGraphVisitor {
        MetadataGraph graph;

        ClasspathContainer cpc;