private static MessageDigest createMessageDigest(
            final String digAlg) throws UnsupportedDigestAlgorithmException {
        try {
            return MessageDigest.getInstance(digAlg);
        } catch (final Exception e) {
            throw new UnsupportedDigestAlgorithmException(
              "Unsupported algorithm in HTTP Digest authentication: "
               + digAlg);
        }
    }
@deprecated This constructor is deprecated to enforce the use of {@link StandardCharsets#UTF_8} encoding
in compliance with RFC 7616 for HTTP Digest Access Authentication. Use the default constructor {@link #DigestScheme()} instead.

@param charset the {@link Charset} set to be used for encoding credentials. This parameter is ignored as UTF-8 is always used.
httpclient5/src/main/java/org/apache/hc/client5/http/impl/auth/DigestScheme.java