public Serializable generateId(Session session) {
        //ignore the argument - just call the Random:
        return Long.toString(getRandom().nextLong());
    }
Returns the String value of the configured {@link Random}'s {@link Random#nextLong() nextLong()} invocation.

@param session the {@link Session} instance to which the ID will be applied.
@return the String value of the configured {@link Random}'s {@link Random#nextLong()} invocation.
core/src/main/java/org/apache/shiro/session/mgt/eis/RandomSessionIdGenerator.java