* #collectValueFromNonCancelledFuture}. As this is called after the subclass is constructed,
   * we're guaranteed to have properly initialized the subclass.
   */
  final void init() {
    /*
     * requireNonNull is safe because this is called from the constructor after `futures` is set but
     * before releaseResources could be called (because we have not yet set up any of the listeners

    public V apply(@ParametricNullness K key) {
      V result = map.get(key);
      checkArgument(result != null || map.containsKey(key), "Key '%s' not present in map", key);
      // The unchecked cast is safe because of the containsKey check.
      return uncheckedCastNullableTToT(result);
    }

    @Override
    public boolean equals(@Nullable Object o) {
      if (o instanceof FunctionForMapNoDefault) {

         *            sqrtFloor^2 <= x < (sqrtFloor + 1)^2
         * halfSquare - sqrtFloor <= x < halfSquare + sqrtFloor + 1
         * so |x - halfSquare| <= sqrtFloor.  Therefore, it's safe to treat x - halfSquare as a
         * signed long, so lessThanBranchFree is safe for use.
         */
        return sqrtFloor + lessThanBranchFree(halfSquare, x);
    }
    throw new AssertionError();
  }

  /**

import okio.Buffer
import okio.BufferedSink
import okio.ByteString

/**
 * An [RFC 6455][rfc_6455]-compatible WebSocket frame writer.
 *
 * This class is not thread safe.
 *
 * [rfc_6455]: http://tools.ietf.org/html/rfc6455
 */
class WebSocketWriter(
  private val isClient: Boolean,
  val sink: BufferedSink,
  val random: Random,
  private val perMessageDeflate: Boolean,

 * contract.
 *
 * <p>The {@code standard} methods and the 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 Louis Wasserman
 * @since 12.0
 */
@GwtIncompatible
public abstract class ForwardingNavigableMap<K extends @Nullable Object, V extends @Nullable Object>

 * contract.
 *
 * <p>The {@code standard} methods and the 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 Louis Wasserman
 * @since 12.0
 */
@GwtIncompatible
public abstract class ForwardingNavigableMap<K extends @Nullable Object, V extends @Nullable Object>

        NetServerEnumIterator iterator = new NetServerEnumIterator(parent, treeHandle, "*", 0, null);

        iterator.close();
        iterator.close(); // Second close should be safe

        // Then: Tree handle should be released only once
        verify(treeHandle, times(1)).release();
    }

    @Test
    @DisplayName("Iterator should handle filter that rejects all entries")

        Mockito.when(mockTransport.acquire()).thenReturn(mockTransport);
    }

    /**
     * Test that concurrent tree operations are thread-safe with CopyOnWriteArrayList.
     */
    @Test
    public void testConcurrentTreeOperationsThreadSafe() throws Exception {
        // Given

     * , java.lang.String)
     */
    @Override
    public void updateSessionId(final String oldSessionId, final String newSessionId) {
        // not MT-safe
        final Queue<UrlQueueImpl<Long>> urlQueueList = dataHelper.getUrlQueueList(oldSessionId);
        // overwrite
        dataHelper.addUrlQueueList(newSessionId, urlQueueList);

 * currently supporting Kryo and JavaBin serialization formats. The serializer
 * type is determined by the crawler data serializer configuration.
 * </p>
 * <p>
 * The class is thread-safe and uses ThreadLocal to maintain Kryo instances
 * per thread to avoid synchronization overhead.
 * </p>
 *
 */
public class DataSerializer {

    /** Logger for this class. */