code: def _get_grad_vector(model):
      return np.concatenate(
          [
              p.grad.cpu().numpy().ravel().copy()
              for p in model.parameters()
          ]
      )
  
file_path: pfrl/tests/utils_tests/test_clip_l2_grad_norm.py
imports: import timeit
  from logging import getLogger
  import numpy
  import pytest
  import torch
  from torch import nn
  from pfrl.utils import clip_l2_grad_norm_
label_desc: Use image node_id 1 for calling a global function with example usage: _get_grad_vector(model) and returns: np