},
		wantErr: io.ErrUnexpectedEOF,
	}, {
		inputData: padInput("0\n"),
		inputHdrs: map[string]string{paxGNUSparseMajor: "1", paxGNUSparseMinor: "0"},
		wantMap:   sparseDatas{},
	}, {
		inputData: padInput("0\n")[:blockSize-1] + "#",
		inputHdrs: map[string]string{paxGNUSparseMajor: "1", paxGNUSparseMinor: "0"},
		wantMap:   sparseDatas{},
	}, {
		inputData: padInput("0"),

    private final ImmutableMap<E, Integer> inputSet;
    private final int mask;

    SubSet(ImmutableMap<E, Integer> inputSet, int mask) {
      this.inputSet = inputSet;
      this.mask = mask;
    }

    @Override
    public Iterator<E> iterator() {
      return new UnmodifiableIterator<E>() {
        final ImmutableList<E> elements = inputSet.keySet().asList();
        int remainingSetBits = mask;

    private final ImmutableMap<E, Integer> inputSet;
    private final int mask;

    SubSet(ImmutableMap<E, Integer> inputSet, int mask) {
      this.inputSet = inputSet;
      this.mask = mask;
    }

    @Override
    public Iterator<E> iterator() {
      return new UnmodifiableIterator<E>() {
        final ImmutableList<E> elements = inputSet.keySet().asList();
        int remainingSetBits = mask;