code: def test_mask(func, dtype):
      torch.manual_seed(42)
      x = torch.randn(2, 6, dtype=dtype)
      x[:, 3:] = -float("inf")
      x0 = x[:, :3]
  
      y = func(x)
      y0 = func(x0)
  
      y[:, :3] -= y0
  
      assert torch.allclose(y, torch.zeros_like(y))
  
imports: import pytest
  import torch
  from ludwig.utils.entmax.activations import Entmax15, Sparsemax
  from ludwig.utils.entmax.root_finding import entmax_bisect, sparsemax_bisect
label_desc: Use image node_id 1 for calling a global function with example usage: test_mask(func, dtype) without return types