code: def test_data_grad():
      v = nn.Variable([2, 3, 4])
      v.d[...] = np.random.randn(*v.shape)
      assert v.d is not v.g
      assert not np.all(v.d == v.g)
  
imports: import pytest
  import numpy
  import nnabla
  from nnabla.testing import assert_allclose
label_desc: Use image node_id 5 for calling a global function with example usage: test_data_grad() without return types