@Override
    public byte[] getBytes() {
        return this.bytes;
    }
Implemented by subclasses, this specifies the {@link MessageDigest MessageDigest} algorithm name
to use when performing the hash.

@return the {@link MessageDigest MessageDigest} algorithm name to use when performing the hash.
crypto/hash/src/main/java/org/apache/shiro/crypto/hash/AbstractHash.java