public static String getUserName(final JwtClaims jwtClaims) {
        LOGGER.debug(() -> "Claim value " + USER_NAME + "=" + jwtClaims.getClaimValue(USER_NAME));
        final String userId = (String) jwtClaims.getClaimValue(USER_NAME);
        return removePrefix(userId);
    }
Get the JSON Web Signature from the specified request header
stroom-security/stroom-security-common-impl/src/main/java/stroom/security/common/impl/JwtUtil.java