code: def forward(self, x, mask):
      out = super().forward(x)
      if mask.is_floating_point():
          out = out * mask
      else:
          # must cast BoolTensor in older torch versions
          out = out * mask.type_as(out)
      return out
  
imports: import pytest
  import torch
  import deepspeed
  from deepspeed.accelerator import get_accelerator
  from copy import deepcopy
  from unit.common import DistributedTest
label_desc: Use image node_id 1 for calling the MaskedLinear obj's underlying member method code with example usage: obj.forward(x, mask) and returns: out