code: def grab_idx(x,i,batch_first:bool=True):
      "Grab the `i`-th batch in `x`, `batch_first` stating the batch dimension."
      if batch_first: return ([o[i].cpu() for o in x]   if is_listy(x) else x[i].cpu())
      else:           return ([o[:,i].cpu() for o in x] if is_listy(x) else x[:,i].cpu()f grab_idx(x,i,batch_first:bool=True):
      "Grab the `i`-th batch in `x`, `batch_first` stating the batch dimension."
      if batch_first: return ([o[i].cpu() for o in x]   if is_listy(x) else x[i].cpu())
      else:           return ([o[:,i].cpu() for o in x] if is_listy(x) else x[:,i].cpu())
docs: Grab the `i`-th batch in `x`, `batch_first` stating the batch dimension.