* multiset "read through" to the specified multiset, and attempts to modify the returned multiset
   * result in an {@link UnsupportedOperationException}.
   *
   * <p>The returned multiset will be serializable if the specified multiset is serializable.
   *
   * @param multiset the multiset for which an unmodifiable view is to be generated
   * @return an unmodifiable view of the multiset
   */

import com.google.errorprone.annotations.DoNotCall;
import com.google.errorprone.annotations.concurrent.LazyInit;
import java.io.InvalidObjectException;
import java.io.ObjectInputStream;
import java.io.Serializable;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.NavigableSet;
import java.util.SortedSet;

  @GwtCompatible(serializable = true)
  public <S extends T> Ordering<S> reverse() {
    return new ReverseOrdering<>(this);
  }

  /**
   * Returns an ordering that treats {@code null} as less than all other values and uses {@code
   * this} to compare non-null values.
   *
   * <p>The returned object is serializable if this object is serializable.
   *

   * method returns instances of a different class than {@code factory.get()} does.
   *
   * <p>The multimap is serializable if {@code map}, {@code factory}, the collections generated by
   * {@code factory}, and the multimap contents are all serializable.
   *
   * <p>The multimap is not threadsafe when any concurrent operations update the multimap, even if

import com.google.errorprone.annotations.DoNotCall;
import com.google.errorprone.annotations.DoNotMock;
import java.io.InvalidObjectException;
import java.io.ObjectInputStream;
import java.io.Serializable;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.NoSuchElementException;
import java.util.function.Function;

import com.google.errorprone.annotations.DoNotCall;
import com.google.errorprone.annotations.concurrent.LazyInit;
import java.io.InvalidObjectException;
import java.io.ObjectInputStream;
import java.io.Serializable;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;
import java.util.Set;
import java.util.stream.Collector;

   * whether direct or via its collection views, result in an {@code UnsupportedOperationException}.
   *
   * <p>The returned navigable set will be serializable if the specified navigable set is
   * serializable.
   *
   * <p><b>Java 8+ users and later:</b> Prefer {@link Collections#unmodifiableNavigableSet}.
   *
   * @param set the navigable set for which an unmodifiable view is to be returned

import com.google.errorprone.annotations.DoNotCall;
import com.google.errorprone.annotations.DoNotMock;
import java.io.InvalidObjectException;
import java.io.ObjectInputStream;
import java.io.Serializable;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.function.BinaryOperator;
import java.util.function.Function;
import java.util.stream.Collector;

 * @since 2.0
 */
@DoNotMock("Use ImmutableMap.of or another implementation")
@GwtCompatible(serializable = true, emulated = true)
@SuppressWarnings("serial") // we're overriding default serialization
@ElementTypesAreNonnullByDefault
public abstract class ImmutableMap<K, V> implements Map<K, V>, Serializable {

  /**
   * Returns a {@link Collector} that accumulates elements into an {@code ImmutableMap} whose keys

import com.google.common.testing.EqualsTester;
import com.google.common.testing.NullPointerTester;
import java.io.ByteArrayOutputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.AbstractMap;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;