// Bucket name in the format of `BucketName-APPID`
NSString *bucket = @"examplebucket-1250000000";
// Object key, i.e. the full path of a COS object. If the object is in a directory, the path should be "video/xxx/movie.mp4"
NSString *object = @"exampleobject";
[[QCloudCOSXMLService defaultCOSXML] doesObjectExistWithBucket:bucket object:object];

// Bucket name in the format of `BucketName-APPID`
let bucket = "examplebucket-1250000000";
// Object key, i.e. the full path of a COS object. If the object is in a directory, the path should be "video/xxx/movie.mp4"
let object  = "exampleobject";

QCloudCOSXMLService.defaultCOSXML().doesObjectExist(withBucket: bucket, object: object);