code: def test_constant_inf():
      x = F.constant(val=float("-inf"), shape=(2, 3))
      assert x.parent
  
imports: import pytest
  import numpy
  import nnabla.functions
  from nbla_test_utils import list_context
label_desc: Use image node_id 3 for calling a global function with example usage: test_constant_inf() without return types