this.keys = keys;
    this.values = values;
  }

  @Override
  public SampleElements<Entry<K, V>> samples() {
    return SampleElements.mapEntries(keys, values);
  }

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

      super(1, 0, 2, 3, 4);
    }
  }

  public static <K extends @Nullable Object, V extends @Nullable Object>
      SampleElements<Entry<K, V>> mapEntries(SampleElements<K> keys, SampleElements<V> values) {
    return new SampleElements<>(
        mapEntry(keys.e0(), values.e0()),
        mapEntry(keys.e1(), values.e1()),
        mapEntry(keys.e2(), values.e2()),

      super(1, 0, 2, 3, 4);
    }
  }

  public static <K extends @Nullable Object, V extends @Nullable Object>
      SampleElements<Entry<K, V>> mapEntries(SampleElements<K> keys, SampleElements<V> values) {
    return new SampleElements<>(
        mapEntry(keys.e0(), values.e0()),
        mapEntry(keys.e1(), values.e1()),
        mapEntry(keys.e2(), values.e2()),

	if err != nil {
		return nil, osErrToFileErr(err)
	}
	defer d.Close()

	maxEntries := 1000
	if opts.count > 0 && opts.count < maxEntries {
		maxEntries = opts.count
	}

	done := false
	remaining := opts.count

	for !done {
		// Read up to max number of entries.
		fis, err := d.Readdir(maxEntries)
		if err != nil {
			if err == io.EOF {
				break
			}