@Override
    public <T> Flux<T> findIds(Class<T> clazz, Filter filter) {
        MongoCollection<T> collection = context.getCollection(clazz);
        FindPublisher<T> publisher = find(collection,
                filter,
                QueryOptions.newBuilder(1)
                        .projection(ID_ONLY));
        return Flux.from(publisher);
    }
@author James Chen
@implNote 1. We operate in an unsafe way, which means we don't check whether arguments are legal
          or not and so on 2. The publishers of mongo-java-driver are cold and the publishers of
          TurmsMongoOperations are also cold Reference:
          https://github.com/mongodb/mongo/blob/master/src/mongo/shell/utils_sh.js
turms-server-common/src/main/java/im/turms/server/common/storage/mongo/operation/TurmsMongoOperations.java