private static Map<String, String> toHashMap(Entry<String, String>[] entries) {
    return populate(new HashMap<String, String>(), entries);
  }

  // TODO: call conversion constructors or factory methods instead of using
  // populate() on an empty map
  private static <T, M extends Map<T, String>> M populate(M map, Entry<T, String>[] entries) {
    for (Entry<T, String> entry : entries) {
      map.put(entry.getKey(), entry.getValue());
    }

    Builder(int initialCapacity) {
      this.entries = new @Nullable Entry[initialCapacity];
      this.size = 0;
      this.entriesUsed = false;
    }

    private void ensureCapacity(int minCapacity) {
      if (minCapacity > entries.length) {
        entries =
            Arrays.copyOf(
                entries, ImmutableCollection.Builder.expandedCapacity(entries.length, minCapacity));
        entriesUsed = false;

    Collections.sort(entries, Helpers.<K, V>entryComparator(navigableMap.comparator()));

    // some tests assume SEVERAL == 3
    if (entries.size() >= 1) {
      a = entries.get(0);
      if (entries.size() >= 3) {
        b = entries.get(1);
        c = entries.get(2);
      }
    }
  }

  /** Resets the contents of navigableMap to have entries a, c, for the navigation tests. */

      Set<Entry<Object, Object>> entries = cache.asMap().entrySet();
      List<Entry<Object, Object>> warmed = warmUp(cache, WARMUP_MIN, WARMUP_MAX);

      Set<?> expected = Maps.newHashMap(cache.asMap()).entrySet();
      assertThat(entries).containsExactlyElementsIn(expected);
      assertThat(entries.toArray()).asList().containsExactlyElementsIn(expected);

    Set<Entry<@Nullable String, @Nullable Boolean>> entries = map.entrySet();
    assertTrue(entries.contains(Maps.immutableEntry("a", true)));
    assertTrue(entries.contains(Maps.<String, @Nullable Boolean>immutableEntry("b", null)));
    assertTrue(
        entries.contains(Maps.<@Nullable String, @Nullable Boolean>immutableEntry(null, null)));

    assertFalse(entries.contains(Maps.<String, @Nullable Boolean>immutableEntry("c", null)));

  public static class ImmutableBiMapGenerator extends TestStringBiMapGenerator {
    @Override
    protected BiMap<String, String> create(Entry<String, String>[] entries) {
      ImmutableBiMap.Builder<String, String> builder = ImmutableBiMap.builder();
      for (Entry<String, String> entry : entries) {
        builder.put(entry.getKey(), entry.getValue());
      }
      return builder.build();
    }
  }

  }

  @MapFeature.Require(SUPPORTS_PUT)
  public void testPutNotPresentKeyPropagatesToEntries() {
    Collection<Entry<K, V>> entries = multimap().entries();
    assertFalse(entries.contains(Helpers.mapEntry(k3(), v3())));
    multimap().put(k3(), v3());
    assertContains(entries, Helpers.mapEntry(k3(), v3()));
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(SUPPORTS_PUT)

  }

  @Override
  public Set<Entry<K, V>> create(Object... elements) {
    Entry<K, V>[] entries = createArray(elements.length);
    System.arraycopy(elements, 0, entries, 0, elements.length);
    return createFromEntries(entries);
  }

  public abstract Set<Entry<K, V>> createFromEntries(Entry<K, V>[] entries);

  @Override
  @SuppressWarnings("unchecked") // generic arrays make typesafety sad

 * requested entries may be evicted on each cache modification.
 *
 * <p>If {@link #expireAfterWrite expireAfterWrite} or {@link #expireAfterAccess expireAfterAccess}
 * is requested entries may be evicted on each cache modification, on occasional cache accesses, or
 * on calls to {@link Cache#cleanUp}. Expired entries may be counted by {@link Cache#size}, but will

                  @Override
                  protected SortedMap<String, String> create(Entry<String, String>[] entries) {
                    SortedMap<String, String> map = new SafeTreeMap<>();
                    for (Entry<String, String> entry : entries) {
                      map.put(entry.getKey(), entry.getValue());
                    }