code: def isnan(x):
      return x != x
  
imports: from __future__ import print_function, division
  from typing import Optional, Union
  import torch
  import torch.nn.functional
  from torch.autograd import Variable
  from torch.nn.modules.loss import _Loss
label_desc: Use image node_id 8 for calling a global function with example usage: isnan(x) and returns: unknown