code: def test_CUDA_VISIBLE_DEVICES_gets_populated_from_environment_if_no_config(
      self, is_gpu, get_gpu_count, os
  ):
      is_gpu.return_value = True
      get_gpu_count.return_value = 3
      os.environ.get.return_value = "0,1"
      context = Context()
      os.environ.get.assert_called_with("CUDA_VISIBLE_DEVICES", "")
  
      self.assertEqual(context.gpus, [0, 1])
  
file_path: evadb/test/unit_tests/executor/test_execution_context.py
imports: import unittest
  from mock import patch
  from evadb.constants import NO_GPU
  from evadb.executor.execution_context import Context
label_desc: Use image node_id 2 for calling the ExecutionContextTest obj's underlying member method code with example usage: obj.test_CUDA_VISIBLE_DEVICES_gets_populated_from_environment_if_no_config(is_gpu, get_gpu_count, os) without return types