assertFalse(
        "removeAll(emptyCollection) should return false",
        collection.removeAll(MinimalCollection.of()));
    expectUnchanged();
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testRemoveAll_nonePresent() {
    assertFalse(
        "removeAll(disjointCollection) should return false",
        collection.removeAll(MinimalCollection.of(e3())));
    expectUnchanged();
  }

    assertFalse(
        "removeAll(emptyCollection) should return false",
        collection.removeAll(MinimalCollection.of()));
    expectUnchanged();
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testRemoveAll_nonePresent() {
    assertFalse(
        "removeAll(disjointCollection) should return false",
        collection.removeAll(MinimalCollection.of(e3())));
    expectUnchanged();
  }

    collection = getSubjectGenerator().create(arrayAndDuplicate.elements);
    E duplicate = arrayAndDuplicate.duplicate;

    assertTrue(
        "removeAll(intersectingCollection) should return true",
        getList().removeAll(MinimalCollection.of(duplicate)));
    assertFalse(
        "after removeAll(e), a collection should not contain e even "
            + "if it initially contained e more than once.",
        getList().contains(duplicate));
  }

    collection = getSubjectGenerator().create(arrayAndDuplicate.elements);
    E duplicate = arrayAndDuplicate.duplicate;

    assertTrue(
        "removeAll(intersectingCollection) should return true",
        getList().removeAll(MinimalCollection.of(duplicate)));
    assertFalse(
        "after removeAll(e), a collection should not contain e even "
            + "if it initially contained e more than once.",
        getList().contains(duplicate));
  }

func TestWebRequestAuthenticate(t *testing.T) {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	obj, fsDir, err := prepareFS(ctx)
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(fsDir)
	if err = newTestConfig(globalMinioDefaultRegion, obj); err != nil {
		t.Fatal(err)
	}

	creds := globalActiveCred
	token, err := getTokenString(creds.AccessKey, creds.SecretKey)
	if err != nil {

      Set<Object> keys = cache.asMap().keySet();
      assertFalse(keys.remove(null));
      assertFalse(keys.remove(6));
      assertFalse(keys.remove(-6));
      assertFalse(keys.removeAll(asList(null, 0, 15, 1500)));
      assertFalse(keys.retainAll(asList(null, 0, 15, 1500)));
      checkEmpty(keys);
      checkEmpty(cache);
    }
  }

  public void testKeySet_remove() {

        public Iterator<K> iterator() {
          return Iterators.unmodifiableIterator(delegate.keySet().iterator());
        }

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

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

  }

  @Override
  public void testEntrySetRemoveAllNullFromEmpty() {
    try {
      super.testEntrySetRemoveAllNullFromEmpty();
    } catch (RuntimeException tolerated) {
      // GWT's TreeMap.entrySet().removeAll(null) doesn't throws NPE.
    }
  }

  @Override
  public void testEntrySetRetainAllNullFromEmpty() {
    try {
      super.testEntrySetRetainAllNullFromEmpty();
    } catch (RuntimeException tolerated) {

  }

  /**
   * A sensible definition of {@link #removeAll} in terms of {@link #iterator}, using the iterator's
   * {@code remove} method. If you override {@link #iterator}, you may wish to override {@link
   * #removeAll} to forward to this implementation.
   *
   * @since 7.0
   */
  protected boolean standardRemoveAll(Collection<?> collection) {
    return Iterators.removeAll(iterator(), collection);
  }

  /**

    @Override
    public int size() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.size();
    }

    @Override
    public boolean removeAll(Collection<?> collection) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.removeAll(collection);
    }

    @Override
    public boolean isEmpty() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.isEmpty();
    }