assertEquals(0, table.size());
      assertFalse(table.containsRow("foo"));
    } else {
      assertThrows(UnsupportedOperationException.class, () -> table.clear());
    }
  }

  public void testPut() {
    assertNull(table.put("foo", 1, cellValue('a')));
    assertNull(table.put("bar", 1, cellValue('b')));
    assertNull(table.put("foo", 3, cellValue('c')));

@J2ktIncompatible // MapMaker
@NullUnmarked
public class MapMakerTest extends TestCase {
  @GwtIncompatible // NullPointerTester
  public void testNullParameters() throws Exception {
    NullPointerTester tester = new NullPointerTester();
    tester.testAllPublicInstanceMethods(new MapMaker());
  }

  @GwtIncompatible // threads
  static final class DelayingIdentityLoader<T> implements Function<T, T> {
    private final CountDownLatch delayLatch;

    NullPointerTester tester = new NullPointerTester();
    // Necessary until JDK15:
    // https://bugs.openjdk.org/browse/JDK-8202469
    tester.ignore(Equivalence.class.getMethod("wrap", Object.class));

    tester.testAllPublicStaticMethods(Equivalence.class);
    tester.testAllPublicInstanceMethods(Equivalence.equals());
    tester.testAllPublicInstanceMethods(Equivalence.identity());
  }

  @GwtIncompatible // reflection
  public void testNulls() throws Exception {
    NullPointerTester tester = new NullPointerTester();
    tester.testAllPublicStaticMethods(ImmutableMultimap.class);
    tester.ignore(ImmutableListMultimap.class.getMethod("get", Object.class));
    tester.testAllPublicInstanceMethods(ImmutableMultimap.of());
    tester.testAllPublicInstanceMethods(ImmutableMultimap.of("a", 1));
  }

    NullPointerTester tester = new NullPointerTester();
    // Necessary until JDK15:
    // https://bugs.openjdk.org/browse/JDK-8202469
    tester.ignore(Equivalence.class.getMethod("wrap", Object.class));

    tester.testAllPublicStaticMethods(Equivalence.class);
    tester.testAllPublicInstanceMethods(Equivalence.equals());
    tester.testAllPublicInstanceMethods(Equivalence.identity());
  }

    // This benchmark has no concept of "noWorkToDo".
    String upperString = testString.toUpperCase();
    CharSequence testSeq = new StringBuilder(testString);
    CharSequence upperSeq = new StringBuilder(upperString);
    CharSequence[] lhs = new CharSequence[] {testString, testSeq, testString, testSeq};
    CharSequence[] rhs = new CharSequence[] {upperString, upperString, upperSeq, upperSeq};

    boolean dummy = false;

    assertThrows(NullPointerException.class, () -> EquivalenceTester.of(null));
  }

  public void testTest_noData() {
    tester.test();
  }

  public void testTest() {
    Object group1Item1 = new TestObject(1, 1);
    Object group1Item2 = new TestObject(1, 2);
    Object group2Item1 = new TestObject(2, 1);
    Object group2Item2 = new TestObject(2, 2);

    equivalenceMock.expectEquivalent(group1Item1, group1Item2);

    assertThrows(NullPointerException.class, () -> EquivalenceTester.of(null));
  }

  public void testTest_noData() {
    tester.test();
  }

  public void testTest() {
    Object group1Item1 = new TestObject(1, 1);
    Object group1Item2 = new TestObject(1, 2);
    Object group2Item1 = new TestObject(2, 1);
    Object group2Item2 = new TestObject(2, 2);

    equivalenceMock.expectEquivalent(group1Item1, group1Item2);

  public void testNullPointers() {
    NullPointerTester tester = new NullPointerTester();
    tester.testAllPublicStaticMethods(ImmutableSortedMap.class);
    tester.testAllPublicInstanceMethods(ImmutableSortedMap.<String, Integer>naturalOrder());
    tester.testAllPublicInstanceMethods(ImmutableSortedMap.of());
    tester.testAllPublicInstanceMethods(ImmutableSortedMap.of("one", 1));

 * object being tested for equality to the custom interface. {@code ForwardingObject} implements no
 * such custom interfaces directly; they are implemented only in subclasses. Therefore, forwarding
 * {@code equals} would break symmetry, as the forwarding object might consider itself equal to the
 * object being tested, but the reverse could not be true. This behavior is consistent with the