@Bean
    public TurmsMongoClient adminMongoClient(TurmsPropertiesManager propertiesManager) {
        AdminMongoProperties properties = propertiesManager.getLocalProperties()
                .getService()
                .getMongo()
                .getAdmin();
        AdminMongoProperties.WriteConcernProperties writeConcern = properties.getWriteConcern();
        TurmsMongoClient mongoClient = getMongoClient(properties, "admin", Collections.emptySet());
        mongoClient.registerEntitiesByOptions(
                MongoCollectionOptions.of(Admin.class, writeConcern.getAdmin()),
                MongoCollectionOptions.of(AdminRole.class, writeConcern.getAdminRole()));
        return mongoClient;
    }
@author James Chen
@see org.springframework.boot.autoconfigure.data.mongo.MongoReactiveDataAutoConfiguration
turms-service/src/main/java/im/turms/service/storage/mongo/MongoConfig.java