import java.util.Collection;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A {@code Multimap} that cannot hold duplicate key-value pairs. Adding a key-value pair that's
 * already in the multimap has no effect. See the {@link Multimap} documentation for information

import java.util.AbstractCollection;
import java.util.Collection;
import java.util.Iterator;
import java.util.Set;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * This class provides a skeletal implementation of the {@link Multiset} interface. A new multiset
 * implementation can be created easily by extending this class and implementing the {@link

import java.util.NavigableMap;
import java.util.NoSuchElementException;
import java.util.Set;
import java.util.function.BiFunction;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * An implementation of {@code RangeMap} based on a {@code TreeMap}, supporting all optional
 * operations.
 *

import com.google.common.annotations.VisibleForTesting;
import java.util.AbstractMap;
import java.util.Arrays;
import java.util.Map.Entry;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A hash-based implementation of {@link ImmutableMap}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible(serializable = true, emulated = true)
@ElementTypesAreNonnullByDefault

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

/**
 * GWT emulation of {@link com.google.common.collect.ImmutableBiMap}.
 *
 * @author Hayward Chan
 */
@ElementTypesAreNonnullByDefault

import java.util.Set;
import java.util.concurrent.atomic.AtomicBoolean;
import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Tests {@link MapTestSuiteBuilder} by using it against maps that have various negative behaviors.
 *
 * @author George van den Driessche
 */

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.Arrays;
import java.util.LinkedHashMap;
import java.util.Map;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * CompactLinkedHashMap is an implementation of a Map with insertion or LRU iteration order,
 * maintained with a doubly linked list through the entries. All optional operations (put and

import com.google.common.testing.GcFinalization;
import java.lang.ref.WeakReference;
import java.util.Iterator;
import java.util.NoSuchElementException;
import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Unit test for {@code AbstractIterator}.
 *
 * @author Kevin Bourrillion
 */
@SuppressWarnings("serial") // No serialization is used in this test
@GwtCompatible(emulated = true)

import com.google.common.testing.GcFinalization;
import java.lang.ref.WeakReference;
import java.util.Iterator;
import java.util.NoSuchElementException;
import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Unit test for {@code AbstractIterator}.
 *
 * @author Kevin Bourrillion
 */
@SuppressWarnings("serial") // No serialization is used in this test
@GwtCompatible(emulated = true)

import com.google.common.testing.EqualsTester;
import java.util.Collections;
import java.util.Comparator;
import java.util.Optional;
import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Tests for {@code Comparators}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public class ComparatorsTest extends TestCase {