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) {
    }
  }

  }

  /**
   * Not supported. Use {@link #eraseAll} instead.
   *
   * @throws UnsupportedOperationException always
   * @deprecated Use {@link #eraseAll}
   */
  @DoNotCall("Always throws UnsupportedOperationException")
  @Override
  @Deprecated
  public void clear() {
    throw new UnsupportedOperationException();
  }

  /** Associates the value {@code null} with every pair of allowed row and column keys. */

    try {
      assertFalse(
          "removeAll(emptyCollection) should return false or throw "
              + "UnsupportedOperationException",
          collection.removeAll(MinimalCollection.of()));
    } catch (UnsupportedOperationException tolerated) {
    }
    expectUnchanged();
  }

  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)

              });
    } catch (UnsupportedOperationException tolerated) {
    }
    expectUnchanged();
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  public void testReplaceAll_unsupportedNoOpFunction() {
    try {
      getMap().replaceAll((K k, V v) -> v);
    } catch (UnsupportedOperationException tolerated) {
    }
    expectUnchanged();
  }

          v0(),
          putIfAbsent(e0()));
    } catch (UnsupportedOperationException tolerated) {
    }
    expectUnchanged();
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testPutIfAbsent_unsupportedPresentDifferentValue() {
    try {
      getMap().putIfAbsent(k0(), v3());
    } catch (UnsupportedOperationException tolerated) {
    }
    expectUnchanged();
  }

   * UnsupportedOperationException."
   */
  abstract void setCountNoCheckReturnValue(E element, int count);

  private void assertSetCountIncreasingFailure(E element, int count) {
    try {
      setCountNoCheckReturnValue(element, count);
      fail("a call to multiset.setCount() to increase an element's count should throw");
    } catch (UnsupportedOperationException expected) {
    }
  }

          getMap().putIfAbsent(k0(), v0()));
    } catch (UnsupportedOperationException tolerated) {
    }
    expectUnchanged();
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testPutIfAbsent_unsupportedPresentDifferentValue() {
    try {
      getMap().putIfAbsent(k0(), v3());
    } catch (UnsupportedOperationException tolerated) {
    }
    expectUnchanged();
  }

   * 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

    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);

   * @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