private static long convertClaimTimeInSecondsToMs(Number claimValue) {
        return Math.round(claimValue.doubleValue() * 1000);
    }
Decode the given Base64URL-encoded value, parse the resulting JSON as a JSON
object, and return the map of member names to their values (each value being
represented as either a String, a Number, or a List of Strings).

@param split
           the value to decode and parse
@return the map of JSON member names to their String, Number, or String List
        value
@throws OAuthBearerIllegalTokenException
            if the given Base64URL-encoded value cannot be decoded or parsed
clients/src/main/java/org/apache/kafka/common/security/oauthbearer/internals/unsecured/OAuthBearerUnsecuredJws.java