code: def _grad_tanh(x):
      return 1 - x * x
  
imports: import numpy
  import six
  from chainer import backend
  from chainer.backends import cuda
  from chainer.backends import intel64
  from chainer import function
  from chainer import function_node
  from chainer.utils import type_check
  import chainerx
label_desc: Use image node_id 5 for calling a global function with example usage: _grad_tanh(x) and returns: unknown