public static void ClassInitialize()
{
//get a OSS client object
_ossClient = OssClientFactory.CreateOssClientUseHttps();
//get current class name, which is prefix of bucket/object
_className = TestContext.CurrentContext.Test.FullName;
_className = _className.Substring(_className.LastIndexOf('.') + 1).ToLowerInvariant();
//create the bucket
_bucketName = OssTestUtils.GetBucketName(_className);
_ossClient.CreateBucket(_bucketName);
}