code: def test(self, ignore_unused_parameters):
      use_cpu_offload = True
  
      if (
          use_cpu_offload
          and not deepspeed.ops.__compatible_ops__[CPUAdamBuilder.NAME]
      ):
          pytest.skip("cpu-adam is not compatible")
  
      config_dict = {
          "train_micro_batch_size_per_gpu": 2,
          "gradient_accumulation_steps": 2,
          "steps_per_print": 1,
          "zero_optimization": {
              "stage": 2,
              "cpu_offload": use_cpu_offload,
              "ignore_unused_parameters": ignore_unused_parameters,
          },
          "optimizer": {"type": "Adam", "params": {"lr": 1e-3}},
          "fp16": {"enabled": True, "initial_scale_power": 8},
      }
      hidden_dim = 4
  
      model = UnusedParametersModel(hidden_dim=hidden_dim)
      model, _, _, _ = deepspeed.initialize(
          config=config_dict,
          model=model,
          model_parameters=model.parameters(),
      )
  
      data_loader = random_dataloader(
          model=model,
          total_samples=10,
          hidden_dim=hidden_dim,
          device=model.device,
      )
  
      def _loop():
          for n, batch in enumerate(data_loader):
              loss = model(batch[0], batch[1])
              model.backward(loss)
              model.step()
  
      if ignore_unused_parameters:
          _loop()
      else:
          with pytest.raises(AssertionError) as e:
              _loop()
          assert (
              e.value.args
              and "ignore_unused_parameters" in e.value.args[0]
          )
  
file_path: deepspeed/tests/unit/runtime/zero/test_ignore_unused_parameters.py
imports: import pytest
  from unit.common import DistributedTest
  from unit.simple_model import UnusedParametersModel, random_dataloader
  from deepspeed.ops.op_builder import CPUAdamBuilder
  import deepspeed
label_desc: Use image node_id 1 for calling the TestStage2IgnoreUnusedParameters obj's underlying member method code with example usage: obj.test(ignore_unused_parameters) without return types