public Mono<Long> countOwnedGroups(@NotNull Long ownerId) {
        try {
            Validator.notNull(ownerId, "ownerId");
        } catch (ResponseException e) {
            return Mono.error(e);
        }
        return groupRepository.countOwnedGroups(ownerId);
    }
@implNote We don't need to check if the group count with the specified type owned by the
          requester exceeds here because it is implemented in
          {@link GroupService#isAllowedToCreateGroup}
turms-service/src/main/java/im/turms/service/domain/group/service/GroupService.java