when I used
            rand_idx = torch.randperm(len(self.Test))[:self.cifar_len]
            self.Test_shuffeled = self.Test[rand_idx]
          
        def __getitem__(self, index):    
            x1, y1 = self.Test[index]
            x2, y2 = self.Test_shuffeled[index]

it gives this error:
 File "...", line 181, in __init__
    self.Test_shuffeled = self.Test[rand_idx]
  File "....", line 117, in __getitem__
    img, target = self.data[index], self.targets[index]
TypeError: only integer tensors of a single element can be converted to an index

and when I tried self.Test[self.rand_idx[index]] it gives this error:
IndexError: index 10 is out of bounds for dimension 0 with size 10