code: def test_grad_const():
      fun = lambda x: 1.0
      with warnings.catch_warnings(record=True) as w:
          warnings.simplefilter("ignore")
          df = grad(fun)
          assert np.allclose(df(2.0), 0.0)
  
imports: from __future__ import absolute_import
  import autograd.numpy
  import autograd.numpy.random
  from autograd.test_util import check_grads
  from autograd import grad
  import warnings
  import pytest
label_desc: Use image node_id 2 for calling a global function with example usage: test_grad_const() without return types