synchronized (mutex) {
        return delegate().remove(o);
      }
    }

    @Override
    public boolean removeAll(Collection<?> c) {
      synchronized (mutex) {
        return delegate().removeAll(c);
      }
    }

    @Override
    public boolean retainAll(Collection<?> c) {
      synchronized (mutex) {
        return delegate().retainAll(c);
      }

      synchronized (mutex) {
        return delegate().remove(o);
      }
    }

    @Override
    public boolean removeAll(Collection<?> c) {
      synchronized (mutex) {
        return delegate().removeAll(c);
      }
    }

    @Override
    public boolean retainAll(Collection<?> c) {
      synchronized (mutex) {
        return delegate().retainAll(c);
      }

      return get((K) key).remove(value);
    }

    @SuppressWarnings("unchecked")
    @Override
    public Collection<V2> removeAll(@CheckForNull Object key) {
      return transform((K) key, fromMultimap.removeAll(key));
    }

    @Override
    public Collection<V2> replaceValues(@ParametricNullness K key, Iterable<? extends V2> values) {

public final class Sets {
  private Sets() {}

  /**
   * {@link AbstractSet} substitute without the potentially-quadratic {@code removeAll}
   * implementation.
   */
  abstract static class ImprovedAbstractSet<E extends @Nullable Object> extends AbstractSet<E> {
    @Override
    public boolean removeAll(Collection<?> c) {
      return removeAllImpl(this, c);
    }

    @Override
    public boolean retainAll(Collection<?> c) {

	if err != nil {
		t.Fatal(err)
	}

	// Remove the object - to simulate the case where the disk was down when the object
	// was created.
	err = removeAll(pathJoin(disk.String(), bucket, object))
	if err != nil {
		t.Fatal(err)
	}

	// Checking abandoned parts should do nothing

    }.test();
  }

  public void testRemoveAll() {
    List<String> list = newArrayList("a", "b", "c", "d", "e");
    assertTrue(Iterators.removeAll(list.iterator(), newArrayList("b", "d", "f")));
    assertEquals(newArrayList("a", "c", "e"), list);
    assertFalse(Iterators.removeAll(list.iterator(), newArrayList("x", "y", "z")));
    assertEquals(newArrayList("a", "c", "e"), list);
  }

  public void testRemoveIf() {

    }.test();
  }

  public void testRemoveAll() {
    List<String> list = newArrayList("a", "b", "c", "d", "e");
    assertTrue(Iterators.removeAll(list.iterator(), newArrayList("b", "d", "f")));
    assertEquals(newArrayList("a", "c", "e"), list);
    assertFalse(Iterators.removeAll(list.iterator(), newArrayList("x", "y", "z")));
    assertEquals(newArrayList("a", "c", "e"), list);
  }

  public void testRemoveIf() {

	xlStorageDeletedStorage, diskPath, err := newXLStorageTestSetup(t)
	if err != nil {
		t.Fatalf("Unable to create xlStorage test setup, %s", err)
	}
	// removing the disk, used to recreate disk not found error.
	os.RemoveAll(diskPath)

	// TestXLStorage for delete on an removed disk.
	// should fail with disk not found.
	err = xlStorageDeletedStorage.DeleteVol(context.Background(), "Del-Vol", false)
	if err != errDiskNotFound {

func (testServer TestServer) Stop() {
	testServer.cancel()
	testServer.Server.Close()
	testServer.Obj.Shutdown(context.Background())
	os.RemoveAll(testServer.Root)
	for _, ep := range testServer.Disks {
		for _, disk := range ep.Endpoints {
			os.RemoveAll(disk.Path)
		}
	}
}

// Truncate request to simulate unexpected EOF for a request signed using streaming signature v4.

			// Add deadlines such that immediate purge is not
			// perpetually hung here.
			w := xioutil.NewDeadlineWorker(globalDriveConfig.GetMaxTimeout())
			w.Run(func() error {
				return removeAll(entry)
			})
		}
	}
}

const almostFilledPercent = 0.05

func (s *xlStorage) diskAlmostFilled() bool {
	info, err := s.diskInfoCache.Get()
	if err != nil {
		return false