class HttpUtil {

    /**
     * Private constructor.
     */
    private HttpUtil() {
    }

    public static String basicAuthHeader(final String username, final String password) {
        return AUTHORIZATION + ": " + basicAuthHeaderValue(username, password);
    }

    public static String basicAuthHeaderValue(final String username, final String password) {<FILL_FUNCTION_BODY>}
}

        return "Basic " +
                Base64.getEncoder().encodeToString(
                        String.format("%s:%s", Objects.toString(username, ""), Objects.toString(password, ""))
                                .getBytes()
                );
    
<no_super_class>