public Flux<Long> queryGroupManagersAndOwnerId(@NotNull Long groupId) {
        try {
            Validator.notNull(groupId, "groupId");
        } catch (ResponseException e) {
            return Flux.error(e);
        }
        return groupMemberRepository.findGroupManagersAndOwnerId(groupId)
                .map(member -> {
                    GroupMember.Key key = member.getKey();
                    cacheMember(key.getGroupId(), member);
                    return key.getUserId();
                });
    }
@return Possible codes: {@link ResponseStatusCode#OK}
        {@link ResponseStatusCode#SEND_MESSAGE_TO_MUTED_GROUP}
        {@link ResponseStatusCode#SEND_MESSAGE_TO_INACTIVE_GROUP}
        {@link ResponseStatusCode#MUTED_GROUP_MEMBER_SEND_MESSAGE}
turms-service/src/main/java/im/turms/service/domain/group/service/GroupMemberService.java