@Override
    public String format(final Hash hash) {
        return requireNonNull(hash).toBase64();
    }
Returns {@code hash.toBase64()}.

@param hash the hash instance to format into a String.
@return {@code hash.toBase64()}.
@throws NullPointerException if hash is {@code null}.
crypto/hash/src/main/java/org/apache/shiro/crypto/hash/format/Base64Format.java