code: private MongoCredential createCredentail(String userName, String database, String password) {
  		if (StrUtil.hasEmpty(userName, database, database)) {
  			return null;
  		}
  		return MongoCredential.createCredential(userName, database, password.toCharArray());
  	}
docs: 创建{@link MongoCredential}，用于服务端验证
  
  @param userName 用户名
  @param database 数据库名
  @param password 密码
  @return {@link MongoCredential}
  @since 4.1.20