@Override
    public long deleteTicketFromQueue(final String ticketId) {
        val encTicketId = digestIdentifier(ticketId);
        return !StringUtils.isBlank(encTicketId) && getMapInstance().remove(encTicketId) != null ? 1 : 0;
    }
This is {@link AbstractMapBasedTicketRegistry}.

@author Misagh Moayyed
@since 5.2.0
core/cas-server-core-tickets-api/src/main/java/org/apereo/cas/ticket/registry/AbstractMapBasedTicketRegistry.java