auto insert = cache_.insert(std::make_pair(key, entry));
    if (!insert.second) {
      lru_list_.erase(insert.first->second.lru_iterator);
      insert.first->second = entry;
    } else if (max_entries_ > 0 && cache_.size() > max_entries_) {
      cache_.erase(lru_list_.back());
      lru_list_.pop_back();
    }
  }

  bool DeleteLocked(const std::string& key) ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_) {

  if (stat_cache_max_age_env &&
      absl::SimpleAtoi(stat_cache_max_age_env, &value)) {
    stat_cache_max_age = value;
  }
  const char* stat_cache_max_entries_env = std::getenv(kStatCacheMaxEntries);
  if (stat_cache_max_entries_env &&
      absl::SimpleAtoi(stat_cache_max_entries_env, &value)) {
    stat_cache_max_entries = static_cast<size_t>(value);
  }
  stat_cache = std::make_unique<ExpiringLRUCache<GcsFileStat>>(

	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
			}

type sparseArray []byte

func (s sparseArray) entry(i int) sparseElem { return sparseElem(s[i*24:]) }
func (s sparseArray) isExtended() []byte     { return s[24*s.maxEntries():][:1] }
func (s sparseArray) maxEntries() int        { return len(s) / 24 }

type sparseElem []byte

func (s sparseElem) offset() []byte { return s[00:][:12] }

  EXPECT_EQ(value, 43);
  // ...but is no longer valid 2 seconds after the insertion.
  env->SetNowSeconds(6);
  EXPECT_FALSE(cache.Lookup(key, &value));
}

TEST(ExpiringLRUCacheTest, MaxEntries) {
  // max_age of 0 means nothing will be cached.
  tf_gcs_filesystem::ExpiringLRUCache<int> cache1(0, 4);
  cache1.Insert("a", 1);
  int value = 0;
  EXPECT_FALSE(cache1.Lookup("a", &value));

	var p parser
	hdr.Size = p.parseNumeric(blk.toGNU().realSize())
	if p.err != nil {
		return nil, p.err
	}
	s := blk.toGNU().sparse()
	spd := make(sparseDatas, 0, s.maxEntries())
	for {
		for i := 0; i < s.maxEntries(); i++ {
			// This termination condition is identical to GNU and BSD tar.
			if s.entry(i).offset()[0] == 0x00 {
				break // Don't return, need to process extended headers (even if empty)
			}

			spd = invertSparseEntries(sph, hdr.Size)

			// Format the sparse map.
			formatSPD := func(sp sparseDatas, sa sparseArray) sparseDatas {
				for i := 0; len(sp) > 0 && i < sa.MaxEntries(); i++ {
					f.formatNumeric(sa.Entry(i).Offset(), sp[0].Offset)
					f.formatNumeric(sa.Entry(i).Length(), sp[0].Length)
					sp = sp[1:]
				}
				if len(sp) > 0 {
					sa.IsExtended()[0] = 1
				}

		}
	}
}

func TestReadOldGNUSparseMap(t *testing.T) {
	populateSparseMap := func(sa sparseArray, sps []string) []string {
		for i := 0; len(sps) > 0 && i < sa.maxEntries(); i++ {
			copy(sa.entry(i), sps[0])
			sps = sps[1:]
		}
		if len(sps) > 0 {
			copy(sa.isExtended(), "\x80")
		}
		return sps
	}