code: def test_unsafe_flag(self, device, dtype):
      length_type = dtype
      lengths = torch.tensor(
          [0, 2, 3, 0], device=device, dtype=length_type
      )
      data = torch.arange(6, dtype=torch.float, device=device)
  
      # test for error on 1-D lenghts
      with self.assertRaisesRegex(
          RuntimeError, "Expected all rows of lengths along axis"
      ):
          torch._segment_reduce(
              data, "sum", lengths=lengths, axis=0, unsafe=False
          )
  
      # test for error on multi-D lengths
      nd_lengths = torch.tensor(
          [[0, 3, 3, 0], [2, 3, 0, 0]], dtype=length_type, device=device
      )
      nd_data = torch.arange(
          12, dtype=torch.float, device=device
      ).reshape(2, 6)
      with self.assertRaisesRegex(
          RuntimeError, "Expected all rows of lengths along axis"
      ):
          torch._segment_reduce(
              nd_data, "sum", lengths=nd_lengths, axis=1, unsafe=False
          )
  
file_path: pytorch/test/test_segment_reductions.py
imports: from itertools import product
  from functools import partial
  import numpy
  import torch
  from torch.testing._internal.common_device_type import instantiate_device_type_tests, dtypes
  from torch.testing._internal.common_utils import TestCase, run_tests, gradcheck, parametrize, skipIfRocm
label_desc: Use image node_id 7 for calling the TestSegmentReductions obj's underlying member method code with example usage: obj.test_unsafe_flag(device, dtype) without return types