class_docstr: test all input tensors without grad
class_docstr_tok: ["test","all","input","tensors","without","grad"]
code: def test_ckpt_arg_none(self, mask):
      module = DropMaskLinear(HIDDEN_DIM, HIDDEN_DIM)
      inputs = (torch.rand(HIDDEN_DIM), None)
      _test_activation_checkpoint(module, *inputs)
  
imports: import sys
  import torch
  import pytest
  from importlib import util
  from deepspeed.runtime.activation_checkpointing.checkpointing import non_reentrant_checkpoint
  from unit.common import DistributedTest
label_desc: Use image node_id 5 for calling the TestActivationCheckpointWithoutGrad obj's underlying member method code with example usage: obj.test_ckpt_arg_none(mask) without return types