class_docstr: CrypTensor class that uses plaintext PyTorch tensors as underlying backend.
  This class should be used for testing purposes.
code: def neg(self):
      result = self.clone()
      result._tensor.neg_()
      return result
  
imports: import torch
  from crypten import CrypTensor, register_cryptensor
label_desc: Use image node_id 7 for calling the PyTorchTensor obj's underlying member method code with example usage: obj.neg() and returns: result