// operation, we fetch this info from storage, and refresh the cache as well.
func (store *IAMStoreSys) ListGroups(ctx context.Context) (res []string, err error) {
	cache := store.lock()
	defer store.unlock()

	if store.getUsersSysType() == MinIOUsersSysType {
		m := map[string]GroupInfo{}
		err = store.loadGroups(ctx, m)
		if err != nil {
			return
		}
		cache.iamGroupsMap = m

			if HasSuffix(deletePath, SlashSeparator) {
				return errFileNotFound
			}
			// if we have .DS_Store only on macOS
			if runtime.GOOS == globalMacOSName {
				storeFilePath := pathJoin(deletePath, ".DS_Store")
				_, err := Stat(storeFilePath)
				// .DS_Store exists
				if err == nil {
					// delete first
					Remove(storeFilePath)
					// try again
					Remove(deletePath)

	testBuckets := []string{
		// This bucket is used for testing ListObject operations.
		0: "test-bucket-list-object",
		// This bucket will be tested with empty directories
		1: "test-bucket-empty-dir",
		// Will not store any objects in this bucket,
		// Its to test ListObjects on an empty bucket.
		2: "empty-bucket",
		// Listing the case where the marker > last object.
		3: "test-bucket-single-object",
		// Listing uncommon delimiter.