* {@link #iterator}, you may wish to override {@link #toString} to forward to this
   * implementation.
   *
   * @since 7.0
   */
  protected String standardToString() {
    return Collections2.toStringImpl(this);
  }

  /**
   * A sensible definition of {@link #toArray()} in terms of {@link #toArray(Object[])}. If you
   * override {@link #toArray(Object[])}, you may wish to override {@link #toArray} to forward to

   * {@link #iterator}, you may wish to override {@link #toString} to forward to this
   * implementation.
   *
   * @since 7.0
   */
  protected String standardToString() {
    return Collections2.toStringImpl(this);
  }

  /**
   * A sensible definition of {@link #toArray()} in terms of {@link #toArray(Object[])}. If you
   * override {@link #toArray(Object[])}, you may wish to override {@link #toArray} to forward to

  }

  public void testToStringImplWithNullEntries() throws Exception {
    List<@Nullable String> list = new ArrayList<>();
    list.add("foo");
    list.add(null);

    assertThat(Collections2.toStringImpl(list)).isEqualTo(list.toString());
  }

  }

  public void testToStringImplWithNullEntries() throws Exception {
    List<@Nullable String> list = new ArrayList<>();
    list.add("foo");
    list.add(null);

    assertThat(Collections2.toStringImpl(list)).isEqualTo(list.toString());
  }

    for (Object o : c) {
      if (!self.contains(o)) {
        return false;
      }
    }
    return true;
  }

  /** An implementation of {@link Collection#toString()}. */
  static String toStringImpl(Collection<?> collection) {
    StringBuilder sb = newStringBuilderForCollection(collection.size()).append('[');
    boolean first = true;
    for (Object o : collection) {
      if (!first) {
        sb.append(", ");

    for (Object o : c) {
      if (!self.contains(o)) {
        return false;
      }
    }
    return true;
  }

  /** An implementation of {@link Collection#toString()}. */
  static String toStringImpl(Collection<?> collection) {
    StringBuilder sb = newStringBuilderForCollection(collection.size()).append('[');
    boolean first = true;
    for (Object o : collection) {
      if (!first) {
        sb.append(", ");

   * forward to this implementation.
   *
   * @since 7.0
   */
  protected String standardToString() {
    return Maps.toStringImpl(this);
  }

   * forward to this implementation.
   *
   * @since 7.0
   */
  protected String standardToString() {
    return Maps.toStringImpl(this);
  }

    // in a way that modifies their hash codes
    return entrySet().hashCode();
  }

  @Override
  public String toString() {
    return Maps.toStringImpl(this);
  }

    hashmap.put(null, "baz");

    assertThat(Maps.toStringImpl(hashmap)).isEqualTo(hashmap.toString());
  }

  public void testToStringImplWithNullValues() throws Exception {
    Map<String, @Nullable String> hashmap = new HashMap<>();
    hashmap.put("foo", "bar");
    hashmap.put("baz", null);

    assertThat(Maps.toStringImpl(hashmap)).isEqualTo(hashmap.toString());
  }

  @J2ktIncompatible