Represents an Entity-Tag value for use inside HTTP Cache headers.
Encodes the bytes with URL Base64 to a human readable string and returns an ETag struct wrapping it.
Hashes the input bytes with md5 and returns an URL Base64 encoded representation as ETag.
See Implementation
https://tools.ietf.org/html/rfc7232#section-2.3
Represents an Entity-Tag value for use inside HTTP Cache headers.