code: def device_id(request):
      return request.config.getoption("--device_id")
  
imports: import itertools
  import numpy
  import pytest
  import re
  import os
  import sys
  from neon.backends import gen_backend
  from neon.backends.nervanacpu import NervanaCPU
  from neon.layers.container import DeltasTree
label_desc: Use image node_id 2 for calling a global function with example usage: device_id(request) and returns: request