} catch (UnsupportedOperationException e) {
      return;
    }

    map.put(null, unmappedValue);
    Entry<@Nullable K, V> entry = mapEntry(null, unmappedValue);
    assertTrue(entrySet.contains(entry));
    Entry<@Nullable K, @Nullable V> nonEntry = mapEntry(null, null);
    assertFalse(entrySet.contains(nonEntry));
  }

  public void testEntrySetContainsEntryNullKeyMissing() {

import static java.util.Collections.shuffle;

import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Package up sample data for common collections benchmarking.
 *
 * @author Nicholaus Shupe
 */
@NullUnmarked
class CollectionBenchmarkSampleData {
  private final boolean isUserTypeFast;

import static java.util.Collections.shuffle;

import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Package up sample data for common collections benchmarking.
 *
 * @author Nicholaus Shupe
 */
@NullUnmarked
class CollectionBenchmarkSampleData {
  private final boolean isUserTypeFast;

      @Override
      protected char @Nullable [] escape(char c) {
        return replacementMap.get(c);
      }
    };
  }

  // A trivial non-optimized escaper for testing.
  static UnicodeEscaper createSimpleUnicodeEscaper(ImmutableMap<Integer, char[]> replacementMap) {
    return new UnicodeEscaper() {
      @Override
      protected char @Nullable [] escape(int cp) {
        return replacementMap.get(cp);

 * the License.
 */

package com.google.common.base;

import com.google.common.annotations.GwtCompatible;
import org.jspecify.annotations.Nullable;

/**
 * Legacy version of {@link java.util.function.Predicate java.util.function.Predicate}. Determines a
 * true or false value for a given input.
 *

  }

  @Override
  @SuppressWarnings("nullness") // b/192354773 in our checker affects toArray declarations
  public <T extends @Nullable Object> T[] toArray(T[] other) {
    return ObjectArrays.toArrayImpl(this, other);
  }

  @Override
  public boolean contains(@Nullable Object object) {
    try {
      // This set never contains null.  We need to explicitly check here

  }

  public void testCopyOf_nullArray() {
    assertThrows(NullPointerException.class, () -> copyOf((String[]) null));
  }

  public void testCopyOf_arrayContainingOnlyNull() {
    @Nullable String[] array = new @Nullable String[] {null};
    assertThrows(NullPointerException.class, () -> copyOf((String[]) array));
  }

  public void testCopyOf_collection_empty() {
    Collection<String> c = MinimalCollection.of();

import java.nio.ByteBuffer;
import java.nio.charset.Charset;
import org.jspecify.annotations.Nullable;

/**
 * Skeleton implementation of {@link HashFunction} in terms of {@link #newHasher()}.
 *
 * <p>TODO(lowasser): make public
 */
@Immutable
abstract class AbstractHashFunction implements HashFunction {
  @Override
  public <T extends @Nullable Object> HashCode hashObject(
      @ParametricNullness T instance, Funnel<? super T> funnel) {

import java.io.Reader;
import java.util.Iterator;
import org.jspecify.annotations.Nullable;

/**
 * A {@link Reader} that concatenates multiple readers.
 *
 * @author Bin Zhu
 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
final class MultiReader extends Reader {
  private final Iterator<? extends CharSource> it;
  private @Nullable Reader current;

import com.google.common.annotations.GwtCompatible;
import java.util.ArrayList;
import java.util.List;
import java.util.ListIterator;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * A utility similar to {@link IteratorTester} for testing a {@link ListIterator} against a known
 * good reference implementation. As with {@code IteratorTester}, a concrete subclass must provide