} catch (RuntimeException tolerated) {
      // GWT's TreeMap.entrySet().retainAll(null) doesn't throws NPE.
    }
  }

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

  @Override

    } catch (RuntimeException tolerated) {
      // GWT's HashMap.entrySet().retainAll(null) doesn't throws NPE.
    }
  }

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

  @Override

    } catch (RuntimeException tolerated) {
      // GWT's TreeMap.entrySet().retainAll(null) doesn't throws NPE.
    }
  }

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

  @Override

    assertFalse(entries.contains(Maps.<@Nullable String, Boolean>immutableEntry(null, true)));
  }

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

  @Override

      assertTrue(keySet.isEmpty());
    } else {
      assertThrows(UnsupportedOperationException.class, keySet::clear);
    }
    assertInvariants(map);
  }

  public void testKeySetRemoveAllNullFromEmpty() {
    Map<K, V> map;
    try {
      map = makeEmptyMap();
    } catch (UnsupportedOperationException e) {
      return;
    }

    Set<K> keySet = map.keySet();