code: def initialize_grad(parameters):
      for param in parameters.values():
          param.grad.zero()
  
file_path: nnabla/python/test/test_forward_all.py
imports: from six.moves import range
  import pytest
  import numpy
  import nnabla
  import nnabla.functions
  import nnabla.parametric_functions
  from nnabla.testing import assert_allclose
label_desc: Use image node_id 1 for calling a global function with example usage: initialize_grad(parameters) without return types