private static class TestMap extends ForwardingConcurrentMap<String, Integer> {
    final ConcurrentMap<String, Integer> delegate = new ConcurrentHashMap<>();

    @Override
    protected ConcurrentMap<String, Integer> delegate() {
      return delegate;
    }
  }

  public void testPutIfAbsent() {
    TestMap map = new TestMap();
    map.put("foo", 1);

        // Verify filter was called for each element
        verify(mockFilter, times(2)).accept(any(SmbResource.class));
    }

    /**
     * Test iterator with empty delegate.
     */
    @Test
    void testEmptyIterator() {
        // Given
        when(mockDelegate.hasNext()).thenReturn(false);

            for (ClassRealmManagerDelegate delegate : delegates) {
                try {
                    delegate.setupRealm(classRealm, request);
                } catch (Exception e) {
                    logger.error(
                            delegate.getClass().getName() + " failed to setup class realm " + classRealm + ": "

  /** A wrapped future that does not propagate cancellation to its delegate. */
  private static final class NonCancellationPropagatingFuture<V extends @Nullable Object>
      extends AbstractFuture.TrustedFuture<V> implements Runnable {
    @LazyInit private @Nullable ListenableFuture<V> delegate;

    NonCancellationPropagatingFuture(ListenableFuture<V> delegate) {
      this.delegate = delegate;
    }

    @Override
    public void run() {

      extends ForwardingList<E> {
    final List<E> delegate;
    final int delta;

    MisleadingSizeList(List<E> delegate, int delta) {
      this.delegate = delegate;
      this.delta = delta;
    }

    @Override
    protected List<E> delegate() {
      return delegate;
    }

    @Override
    public int size() {
      return delegate.size() + delta;
    }
  }

                context.closeables.add(simplex);
                context.simplexTransferListener = simplex;
            }
            delegate = context.simplexTransferListener;
        } else {
            delegate = new Slf4jMavenTransferListener();
        }
        return new MavenTransferListener(delegate, determineBuildEventListener(context));
    }

    protected String determineMakeBehavior(MavenContext context) {

          // requireNonNull(delegate) is safe for reasons similar to requireNonNull(sequencer).
          submittingTaskQueue.nextExecutor = requireNonNull(delegate);
          delegate = null;
        } else {
          // requireNonNull(delegate) is safe for reasons similar to requireNonNull(sequencer).
          Executor localDelegate = requireNonNull(delegate);
          delegate = null;
          this.task = task;

    Executor delegate =
        new Executor() {
          @Override
          public void execute(Runnable task) {
            if (future.set(null)) {
              awaitUninterruptibly(latch);
            }
            throw new RejectedExecutionException();
          }
        };
    SequentialExecutor executor = new SequentialExecutor(delegate);

        super(original);
        this.in = new Reader() {
            Reader delegate = null;

            @Override
            public int read(char[] cbuf, int off, int len) throws IOException {
                if (delegate == null) {
                    delegate = transform(original);
                }
                return delegate.read(cbuf, off, len);
            }

            @Override

    /**
     * Constructs a CIFS context wrapper with custom credentials.
     *
     * @param delegate the context to wrap
     * @param creds
     *            Credentials to use
     */
    public CIFSContextCredentialWrapper(final AbstractCIFSContext delegate, final Credentials creds) {
        super(delegate);
        this.creds = creds;
    }

    /**
     *
     * {@inheritDoc}
     *