A function that verifies retrieved or generated call id. Should return true for a valid call id. Also it could throw a RejectedCallIdException to reject an ApplicationCall otherwise an illegal call id will be ignored or replaced with generated one.
Generates a fixed length call ID using the specified dictionary. Note that this function generates pseudo-random identifiers via regular java.util.Random and should not be considered as cryptographically secure. Also note that you need to use the same dictionary for CallIdVerifier, otherwise a generated call ID could be discarded or may lead to complete call rejection.