<ipython-input-76-7d079b1ce127> in forward(self, title, content)
     51     def forward(self, title, content):
     52         title = self.encoder_tit(title)
---> 53         title_rehape = torch.cat((torch.index_select(title, 2, torch.LongTensor([0,2])), 
     54                    torch.index_select(title, 2, torch.LongTensor([1]))), dim=2)
     55         title_out_1 = self.title_conv_1(title_rehape)

/home/quoniammm/anaconda3/envs/py3Tfgpu/lib/python3.6/site-packages/torch/autograd/variable.py in index_select(self, dim, index)
    679 
    680     def index_select(self, dim, index):
--> 681         return IndexSelect.apply(self, dim, index)
    682 
    683     def gather(self, dim, index):

RuntimeError: save_for_backward can only save input or output tensors, but argument 0 doesn't satisfy this condition

Here, title is a Variable.But it has the same error.What is the reason for it?
what I want to implement is exchange the position of column 2 and column 1.