human
Solve the following python programming problem given the following code:
def Transform(self, client, photo, callback) : 
    from viewfinder.backend.storage.s3_object_store import S3ObjectStore 
    def _SetPhotoSizeValues(size_values) : 
        (tn_size, med_size, full_size, orig_size) = size_values 
        assert ((photo.tn_size == tn_size) or (photo.tn_size is None)), photo 
        photo.tn_size = tn_size 
        assert ((photo.med_size == med_size) or (photo.med_size is None)), photo 
        photo.med_size = med_size 
        assert ((photo.full_size == full_size) or (photo.full_size is None)), photo 
        photo.full_size = full_size 
        assert ((photo.orig_size == orig_size) or (photo.orig_size is None)), photo 
        photo.orig_size = orig_size 
        self._LogUpdate (photo) 
        if Version._mutate_items : 
            photo.Update (client, partial (callback, photo)) 
else : 
            callback (photo) 
def _OnListKeys(result) : 
        def _GetSizeOrNone(files, suffix) : 
            fname = ((photo.photo_id + '.') + suffix) 
            if (fname in files) : 
                return int (files [fname] ['Size']) 
else : 
                return None 
if (len (result) > 0) : 
            _SetPhotoSizeValues ((_GetSizeOrNone (result, 't'), _GetSizeOrNone (result, 'm'), _GetSizeOrNone (result, 'f'), _GetSizeOrNone (result, 'o'))) 
else : 
            logging.info (('No files found in S3 for photo %s' % photo.photo_id)) 
            callback (photo) 
def _ListPhotoMetadata() : 
        object_store = S3ObjectStore ('photos-viewfinder-co') 
        object_store.ListKeyMetadata (_OnListKeys, prefix = (photo.photo_id + '.'), fields = ['Size', 'Key']) 
client_data = photo.client_data 
    if ((client_data is None) or ('tn_size' not in photo)) : 
        if (not Version._allow_s3_queries) : 
            callback (photo) 
            return 
_ListPhotoMetadata () 
else : 
        _SetPhotoSizeValues ((int (client_data ['tn_size']), int (client_data ['med_size']), int (client_data ['full_size']), int (client_data ['orig_size']))) 

    
    

    Fix the buggy line: if ((client_data is None) or ('tn_size' not in photo)) :
assistant
#Here is Python program to fix the buggy line: if ((client_data is None) or ('tn_size' not in photo)) :
.

if ((client_data is None) or ('tn_size' not in client_data)) :