ArrayListMultimap<@Nullable String, Integer> input = ArrayListMultimap.create();
    input.put(null, 1);
    try {
      ImmutableListMultimap.copyOf((ArrayListMultimap<String, Integer>) input);
      fail();
    } catch (NullPointerException expected) {
    }
  }

  public void testCopyOfNullValue() {
    ArrayListMultimap<String, @Nullable Integer> input = ArrayListMultimap.create();

      @Override
      void assertFailsToDecode(
          BaseEncoding encoding, String cannotDecode, @Nullable String expectedMessage) {
        assertThat(encoding.canDecode(cannotDecode)).isFalse();
      }
    },
    DECODE {
      @Override
      void assertFailsToDecode(
          BaseEncoding encoding, String cannotDecode, @Nullable String expectedMessage) {
        try {
          encoding.decode(cannotDecode);

    try {
      copyOf((String[]) null);
      fail();
    } catch (NullPointerException expected) {
    }
  }

  public void testCopyOf_arrayContainingOnlyNull() {
    @Nullable String[] array = new @Nullable String[] {null};
    try {
      copyOf((String[]) array);
      fail();
    } catch (NullPointerException expected) {
    }
  }

  public void testCopyOf_collection_empty() {

  public void testCopyOfNullKey() {
    HashMultimap<@Nullable String, Integer> input = HashMultimap.create();
    input.put(null, 1);
    try {
      ImmutableSetMultimap.copyOf((Multimap<String, Integer>) input);
      fail();
    } catch (NullPointerException expected) {
    }
  }

  public void testCopyOfNullValue() {
    HashMultimap<String, @Nullable Integer> input = HashMultimap.create();

import java.nio.charset.Charset;
import java.util.concurrent.TimeUnit;
import java.util.regex.Pattern;
import junit.framework.AssertionFailedError;
import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Tests for {@link ForwardingWrapperTester}. Live in a different package to detect reflection
 * access issues, if any.
 *
 * @author Ben Yu
 */
public class ForwardingWrapperTesterTest extends TestCase {

import java.util.Collection;
import java.util.Iterator;
import java.util.Set;
import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Tests for {@link ForwardingMultiset}.
 *
 * @author Hayward Chan
 * @author Louis Wasserman
 */
public class ForwardingMultisetTest extends TestCase {

package com.google.common.testing;

import static com.google.common.truth.Truth.assertThat;

import com.google.common.annotations.GwtCompatible;
import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

/** @author Luiz-Otavio "Z" Zorzella */
@GwtCompatible
public class TearDownStackTest extends TestCase {

  private TearDownStack tearDownStack = new TearDownStack();

import com.google.common.collect.testing.features.CollectionFeature;
import java.lang.reflect.Method;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import org.checkerframework.checker.nullness.qual.Nullable;
import org.junit.Ignore;

/**
 * Tester to make sure the {@code iterator().remove()} implementation of {@code Multiset} works when
 * there are multiple occurrences of elements.
 *
 * @author Louis Wasserman
 */

    }

    void clear() {
      value = null;
    }
  }

  private static final class AvlNode<E extends @Nullable Object> {
    /*
     * For "normal" nodes, the type of this field is `E`, not `@Nullable E` (though note that E is a
     * type that can include null, as in a TreeMultiset<@Nullable String>).
     *
     * For the header node, though, this field contains `null`, regardless of the type of the
     * multiset.

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

/**
 * An immutable sorted set with one or more elements. TODO(jlevy): Consider separate class for a
 * single-element sorted set.
 *
 * @author Jared Levy
 * @author Louis Wasserman
 */