code: def test_ffnet_error(device_id):
      from cntk.ops.tests.ops_test_utils import cntk_device
  
      try_set_default_device(cntk_device(device_id))
  
      np.random.seed(0)
      avg_error = ffnet()
      expected_avg_error = 0.04
      assert np.allclose(
          avg_error, expected_avg_error, atol=TOLERANCE_ABSOLUTE
      )
  
imports: import os, sys
  import numpy
  from cntk.device import try_set_default_device
  from FeedForwardNet import ffnet
label_desc: Use image node_id 1 for calling a global function with example usage: test_ffnet_error(device_id) without return types