}
    }
    return false;
  }

  @Override
  public boolean contains(@Nullable Object rowKey, @Nullable Object columnKey) {
    Map<C, V> row = safeGet(rowMap(), rowKey);
    return row != null && Maps.safeContainsKey(row, columnKey);
  }

  @Override
  public @Nullable V get(@Nullable Object rowKey, @Nullable Object columnKey) {
    Map<C, V> row = safeGet(rowMap(), rowKey);

 * @param <V> the type of the mapped values
 * @since 7.0
 */
@DoNotMock("Use ImmutableTable, HashBasedTable, or another implementation")
@GwtCompatible
public interface Table<
    R extends @Nullable Object, C extends @Nullable Object, V extends @Nullable Object> {
  // TODO(jlevy): Consider adding methods similar to ConcurrentMap methods.

  // Accessors

  /**

  private CacheBuilder<Object, Object> createCacheBuilder(
      @Nullable Integer concurrencyLevel,
      @Nullable Integer initialCapacity,
      @Nullable Integer maximumSize,
      @Nullable DurationSpec expireAfterWrite,
      @Nullable DurationSpec expireAfterAccess,
      @Nullable DurationSpec refresh,
      @Nullable Strength keyStrength,
      @Nullable Strength valueStrength) {

        header);
  }

  private static final class Reference<T> {
    private @Nullable T value;

    @Nullable T get() {
      return value;
    }

    void checkAndSet(@Nullable T expected, @Nullable T newValue) {
      if (value != expected) {
        throw new ConcurrentModificationException();
      }
      value = newValue;
    }

import org.jspecify.annotations.Nullable;

/**
 * Tests for {@code AbstractMapEntry}.
 *
 * @author Mike Bostock
 */
@GwtCompatible
@NullMarked
public class AbstractMapEntryTest extends TestCase {
  private static final @Nullable String NK = null;
  private static final @Nullable Integer NV = null;

  private static <K extends @Nullable Object, V extends @Nullable Object> Entry<K, V> entry(
      K key, V value) {

    public static Object good(
        String a,
        int b,
        // oneConstantOnly doesn't matter since it's not nullable and can be only 1 value.
        @SuppressWarnings("unused") OneConstantEnum oneConstantOnly,
        // noConstant doesn't matter since it can only be null
        @SuppressWarnings("unused") @Nullable NoConstantEnum noConstant) {
      return new GoodEquals(a, b);
    }

    // instance method ignored

                    @Nonnull ProtoSession session,
                    @Nullable RequestTrace trace,
                    @Nullable Source installationSettingsSource,
                    @Nullable Source projectSettingsSource,
                    @Nullable Source userSettingsSource,
                    @Nullable UnaryOperator<String> interpolationSource) {
                super(session, trace);

 * @author Ben Yu
 * @since 12.0
 */
/*
 * A nullable bound would let users create a TypeParameter instance for a parameter with a nullable
 * bound. However, it would also let them create `new TypeParameter<@Nullable T>() {}`, which
 * wouldn't behave as users might expect. Additionally, it's not clear how the TypeToken API could
 * support even a "normal" `TypeParameter<T>` when `<T>` has a nullable bound. (See the discussion

import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Tests for {@link Functions}.
 *
 * @author Mike Bostock
 * @author Vlad Patryshev
 */
@GwtCompatible
@NullMarked
public class FunctionsTest extends TestCase {

  public void testIdentity_same() {
    Function<@Nullable String, @Nullable String> identity = Functions.identity();
    assertThat(identity.apply(null)).isNull();

    private @Nullable Set<@Nullable N> visitedNodes;

    private Undirected(BaseGraph<N> graph) {
      super(graph);
      this.visitedNodes = Sets.newHashSetWithExpectedSize(graph.nodes().size() + 1);
    }

    @Override
    protected @Nullable EndpointPair<N> computeNext() {
      while (true) {
        /*