code: def ref_clip_grad_by_value(x, min_, max_):
      y = np.copy(x)
      return y
  
imports: import pytest
  import numpy
  import nnabla.functions
  from nbla_test_utils import list_context
label_desc: Use image node_id 1 for calling a global function with example usage: ref_clip_grad_by_value(x, min_, max_) and returns: y