code: def test_tanh():
      fun = lambda x: 3.0 * np.tanh(x)
      check_grads(fun)(npr.randn())
  
imports: from __future__ import absolute_import
  import autograd.numpy
  import autograd.numpy.random
  from autograd.test_util import check_grads
  from autograd import grad
label_desc: Use image node_id 16 for calling a global function with example usage: test_tanh() without return types