// IsValid - returns true if input string is a valid
// storage class kind supported.
func IsValid(sc string) bool {
	return sc == RRS || sc == STANDARD
}

// UnmarshalText unmarshals storage class from its textual form into
// storageClass structure.
func (sc *StorageClass) UnmarshalText(b []byte) error {
	scStr := string(b)
	if scStr == "" {
		return nil
	}
	s, err := parseStorageClass(scStr)
	if err != nil {

	}
	return etag, nil
}

// Parse parses s as an S3 ETag, returning the result.
// The string can be an encrypted, singlepart
// or multipart S3 ETag. It returns an error if s is
// not a valid textual representation of an ETag.
func Parse(s string) (ETag, error) {
	const strict = false
	return parse(s, strict)
}

// parse parse s as an S3 ETag, returning the result.
// It operates in one of two modes: