import java.util.function.BinaryOperator;
import java.util.function.Function;
import java.util.stream.Collector;
import java.util.stream.Collectors;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A {@link BiMap} whose contents will never change, with many other important properties detailed
 * at {@link ImmutableCollection}.
 *
 * @author Jared Levy
 * @since 2.0
 */

import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.SortedSet;
import java.util.TreeMap;
import java.util.TreeSet;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * An immutable builder for {@link Multimap} instances, letting you independently select the desired
 * behaviors (for example, ordering) of the backing map and value-collections. Example:
 *
 * <pre>{@code

import java.util.LinkedHashSet;
import java.util.List;
import java.util.ListIterator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import org.checkerframework.checker.nullness.qual.Nullable;

@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public class Helpers {
  // Clone of Objects.equal
  static boolean equal(@Nullable Object a, @Nullable Object b) {

import java.util.Collections;
import java.util.EnumSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Base class for {@link ImmutableSet} and {@link ImmutableSortedSet} tests.
 *
 * @author Kevin Bourrillion
 * @author Jared Levy
 */
@GwtCompatible(emulated = true)

import java.lang.reflect.Modifier;
import java.lang.reflect.Type;
import java.lang.reflect.TypeVariable;
import java.util.Arrays;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Wrapper around either a {@link Method} or a {@link Constructor}. Convenience API is provided to
 * make common reflective operation easier to deal with, such as {@link #isPublic}, {@link

import java.util.function.BiPredicate;
import java.util.stream.Collector;
import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Tests for {@link ImmutableMultiset}.
 *
 * @author Jared Levy
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public class ImmutableMultisetTest extends TestCase {

import java.util.Set;
import java.util.concurrent.Callable;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.ExecutionException;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * LocalCache emulation for GWT.
 *
 * @param <K> the base key type
 * @param <V> the base value type
 * @author Charles Fry
 * @author Jon Donovan
 */

import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
import java.util.NoSuchElementException;
import java.util.Set;
import java.util.Stack;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Most of the logic for {@link IteratorTester} and {@link ListIteratorTester}.
 *
 * @param <E> the type of element returned by the iterator

import java.util.List;
import java.util.Spliterator;
import java.util.Spliterators;
import java.util.function.Predicate;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A {@link Collection} whose contents will never change, and which offers a few additional
 * guarantees detailed below.
 *

import java.util.Map.Entry;
import java.util.function.Function;
import java.util.stream.Collector;
import java.util.stream.Stream;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A {@link ListMultimap} whose contents will never change, with many other important properties
 * detailed at {@link ImmutableCollection}.
 *
 * <p>See the Guava User Guide article on <a href=