@Override
    public long deleteSingleTicket(final Ticket ticketToDelete) {
        return FunctionUtils.doUnchecked(() -> {
            val ticketId = digestIdentifier(ticketToDelete.getId());
            LOGGER.debug("Deleting ticket [{}]", ticketId);
            val metadata = ticketCatalog.find(ticketToDelete);
            val collectionName = getTicketCollectionInstanceByMetadata(metadata);
            val updateTime = firestore.collection(collectionName).document(ticketId).delete().get().getUpdateTime();
            LOGGER.debug("Deleted ticket [{}] from [{}] @ [{}]", ticketToDelete.getId(), collectionName, updateTime);
            return 1;
        });
    }
This is {@link GoogleCloudFirestoreTicketRegistry}.

@author Misagh Moayyed
@since 7.0.0
support/cas-server-support-gcp-firestore-ticket-registry/src/main/java/org/apereo/cas/ticket/registry/GoogleCloudFirestoreTicketRegistry.java