* the range set that are {@linkplain Range#isConnected(Range) connected} with it. Moreover, if
   * {@code range} is empty, this is a no-op.
   *
   * @throws UnsupportedOperationException if this range set does not support the {@code add}
   *     operation
   */
  void add(Range<C> range);

  /**
   * Removes the specified range from this {@code RangeSet} (optional operation). After this

    sortedMap.put("three", 3);
    return sortedMap;
  }

  @Override
  protected String getKeyNotInPopulatedMap() throws UnsupportedOperationException {
    return "minus one";
  }

  @Override
  protected Integer getValueNotInPopulatedMap() throws UnsupportedOperationException {
    return -1;
  }

  @J2ktIncompatible // https://youtrack.jetbrains.com/issue/KT-58242/ undefined behavior (crash)
  @Override

    Set<Integer> nodes = network.nodes();
    assertThrows(UnsupportedOperationException.class, () -> nodes.add(N2));
    addNode(N1);
    assertThat(network.nodes()).containsExactlyElementsIn(nodes);
  }

  @Override
  @Test
  public void edges_checkReturnedSetMutability() {
    Set<String> edges = network.edges();
    assertThrows(UnsupportedOperationException.class, () -> edges.add(E12));
    addEdge(N1, N2, E12);

      throw new UnsupportedOperationException();
    }

    @Override
    public void putAll(Table<? extends R, ? extends C, ? extends V> table) {
      throw new UnsupportedOperationException();
    }

    @Override
    public @Nullable V remove(@Nullable Object rowKey, @Nullable Object columnKey) {
      throw new UnsupportedOperationException();
    }

    @Override

   * @throws UnsupportedOperationException always
   * @deprecated Unsupported operation.
   */
  @Deprecated
  @Override
  @DoNotCall("Always throws UnsupportedOperationException")
  public final void add(int index, E element) {
    throw new UnsupportedOperationException();
  }

  /**
   * Guaranteed to throw an exception and leave the list unmodified.
   *
   * @throws UnsupportedOperationException always

    }
  }

  public void testKeySet_addNotSupported() {
    for (LoadingCache<Object, Object> cache : caches()) {
      assertThrows(UnsupportedOperationException.class, () -> cache.asMap().keySet().add(1));

      assertThrows(
          UnsupportedOperationException.class, () -> cache.asMap().keySet().addAll(asList(1, 2)));
    }
  }


  public void testKeySet_clear() {

    }

    @Override
    public E belowSamplesLesser() {
      throw new UnsupportedOperationException();
    }

    @Override
    public E belowSamplesGreater() {
      throw new UnsupportedOperationException();
    }

    @Override
    public E aboveSamplesLesser() {
      throw new UnsupportedOperationException();
    }

    @Override
    public E aboveSamplesGreater() {

  public boolean retainAll(Collection<?> elementsToRetain) {
    throw up();
  }

  @Override
  public void clear() {
    throw up();
  }

  private static UnsupportedOperationException up() {
    throw new UnsupportedOperationException();
  }

      fail("Expected NullPointerException or UnsupportedOperationException");
    } catch (NullPointerException | UnsupportedOperationException expected) {
    }
  }

  public void testMergeNullFunction() {
    try {
      getMap().merge(k0(), v3(), null);
      fail("Expected NullPointerException or UnsupportedOperationException");
    } catch (NullPointerException | UnsupportedOperationException expected) {
    }
  }

    assertThrows(
        UnsupportedOperationException.class, () -> putAll(MinimalCollection.of(e3(), e0())));
    expectUnchanged();
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testPutAll_unsupportedAllPresent() {
    try {
      putAll(MinimalCollection.of(e0()));
    } catch (UnsupportedOperationException tolerated) {
    }
    expectUnchanged();